Re-factor how the ESLint no-var rule is enabled in the src/ folder

This simplifies/consolidates the ESLint configuration slightly in the `src/` folder, and prevents the addition of any new files where `var` is being used.[1]
Hence we no longer need to manually add `/* eslint no-var: error */` in files, which is easy to forget, and can instead disable the rule in the `src/core/` files where `var` is still in use.

---
[1] Obviously the `no-var` rule can, in the same way as every other rule, be disabled on a case-by-case basis where actually necessary.

src/.eslintrc

@@ -1,6 +1,6 @@
 {
   "extends": [
-    "../../.eslintrc"
+    "../.eslintrc"
   ],
 
   "rules": {

src/core/.eslintrc

@@ -4,7 +4,7 @@
   },
 
   "extends": [
-    "../../.eslintrc"
+    "../.eslintrc"
   ],
 
   "env": {

src/core/annotation.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint no-var: error */
 
 import {
   AnnotationBorderStyleType,

src/core/arithmetic_decoder.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint no-var: error */
 
 // Table C-2
 const QeTable = [

src/core/bidi.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import { warn } from "../shared/util.js";
 

src/core/ccitt_stream.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import { Dict, isDict } from "./primitives.js";
 import { CCITTFaxDecoder } from "./ccitt.js";

src/core/cff_parser.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import {
   bytesToString,

src/core/charsets.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint no-var: error */
 
 // prettier-ignore
 const ISOAdobeCharset = [

src/core/chunked_stream.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint no-var: error */
 
 import {
   arrayByteLength,

src/core/cmap.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import {
   CMapCompressionType,

src/core/core_utils.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint no-var: error */
 
 import { assert, BaseException, warn } from "../shared/util.js";
 

src/core/crypto.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import {
   bytesToString,

src/core/document.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint no-var: error */
 
 import {
   assert,

src/core/evaluator.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import {
   AbortException,

src/core/font_renderer.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import {
   bytesToString,

src/core/fonts.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import {
   assert,

src/core/function.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import { Dict, isDict, isStream, Ref } from "./primitives.js";
 import {

src/core/glyphlist.js

@@ -13,6 +13,7 @@
  * limitations under the License.
  */
 /* no-babel-preset */
+/* eslint-disable no-var */
 
 var getLookupTableFactory = require("./core_utils.js").getLookupTableFactory;
 

src/core/image.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import { assert, FormatError, ImageKind, info, warn } from "../shared/util.js";
 import { isName, isStream, Name } from "./primitives.js";

src/core/image_utils.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint no-var: error */
 
 import { assert, info, shadow, unreachable } from "../shared/util.js";
 import { RefSetCache } from "./primitives.js";

src/core/jbig2.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import { BaseException, shadow } from "../shared/util.js";
 import { log2, readInt8, readUint16, readUint32 } from "./core_utils.js";

src/core/jpg.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import { assert, BaseException, warn } from "../shared/util.js";
 import { readUint16 } from "./core_utils.js";

src/core/jpx.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import { BaseException, info, warn } from "../shared/util.js";
 import { log2, readUint16, readUint32 } from "./core_utils.js";

src/core/metrics.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import { getLookupTableFactory } from "./core_utils.js";
 

src/core/murmurhash3.js

@@ -16,7 +16,6 @@
  * Based on https://code.google.com/p/smhasher/wiki/MurmurHash3.
  * Hashes roughly 100 KB per millisecond on i7 3.4 GHz.
  */
-/* eslint no-var: error */
 
 import { isArrayBuffer, isString } from "../shared/util.js";
 

src/core/obj.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import {
   assert,

src/core/operator_list.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import { assert, ImageKind, OPS, warn } from "../shared/util.js";
 

src/core/parser.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint no-var: error */
 
 import {
   Ascii85Stream,

src/core/pattern.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import {
   assert,

src/core/primitives.js

@@ -12,7 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* uses XRef */
+/* eslint-disable no-var */
 
 import { assert, unreachable } from "../shared/util.js";
 

src/core/ps_parser.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint no-var: error */
 
 import { FormatError, shadow } from "../shared/util.js";
 import { EOF } from "./primitives.js";

src/core/standard_fonts.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint no-var: error */
 
 import { getLookupTableFactory } from "./core_utils.js";
 

src/core/stream.js

@@ -18,6 +18,7 @@
  * of XPDF's implementation, made available under the Apache 2.0 open source
  * license.
  */
+/* eslint-disable no-var */
 
 import { FormatError, stringToBytes, unreachable } from "../shared/util.js";
 import { isDict } from "./primitives.js";

src/core/type1_parser.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import { getEncoding } from "./encodings.js";
 import { isWhiteSpace } from "./core_utils.js";

src/core/unicode.js

@@ -13,6 +13,7 @@
  * limitations under the License.
  */
 /* no-babel-preset */
+/* eslint-disable no-var */
 
 var getLookupTableFactory = require("./core_utils.js").getLookupTableFactory;
 

src/core/worker.js

@@ -12,6 +12,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+/* eslint-disable no-var */
 
 import {
   AbortException,

src/core/worker_stream.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint no-var: error */
 
 import { assert } from "../shared/util.js";
 

src/core/writer.js

@@ -12,7 +12,6 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-/* eslint no-var: error */
 
 import { bytesToString, escapeString, warn } from "../shared/util.js";
 import { Dict, isDict, isName, isRef, isStream, Name } from "./primitives.js";

src/shared/.eslintrc

@@ -1,10 +0,0 @@
-{
-  "extends": [
-    "../../.eslintrc"
-  ],
-
-  "rules": {
-    // ECMAScript 6
-    "no-var": "error",
-  },
-}