Stop special-casing the dict parameter in the Jbig2Stream/JpegStream/JpxStream constructors

For all of the other `DecodeStream`s we're not passing in a `Dict`-instance manually, but instead get it from the `stream`-parameter. Hence there's no particularly good reason, as far as I can tell, to not do the same thing in `Jbig2Stream`/`JpegStream`/`JpxStream` as well.

src/core/jbig2_stream.js

@@ -23,12 +23,12 @@ import { shadow } from "../shared/util.js";
  * the stream behaves like all the other DecodeStreams.
  */
 class Jbig2Stream extends DecodeStream {
-  constructor(stream, maybeLength, dict, params) {
+  constructor(stream, maybeLength, params) {
     super(maybeLength);
 
     this.stream = stream;
+    this.dict = stream.dict;
     this.maybeLength = maybeLength;
-    this.dict = dict;
     this.params = params;
   }
 

src/core/jpeg_stream.js

@@ -23,7 +23,7 @@ import { shadow } from "../shared/util.js";
  * like all the other DecodeStreams.
  */
 class JpegStream extends DecodeStream {
-  constructor(stream, maybeLength, dict, params) {
+  constructor(stream, maybeLength, params) {
     // Some images may contain 'junk' before the SOI (start-of-image) marker.
     // Note: this seems to mainly affect inline images.
     let ch;
@@ -37,8 +37,8 @@ class JpegStream extends DecodeStream {
     super(maybeLength);
 
     this.stream = stream;
+    this.dict = stream.dict;
     this.maybeLength = maybeLength;
-    this.dict = dict;
     this.params = params;
   }
 

src/core/jpx_stream.js

@@ -22,12 +22,12 @@ import { shadow } from "../shared/util.js";
  * the stream behaves like all the other DecodeStreams.
  */
 class JpxStream extends DecodeStream {
-  constructor(stream, maybeLength, dict, params) {
+  constructor(stream, maybeLength, params) {
     super(maybeLength);
 
     this.stream = stream;
+    this.dict = stream.dict;
     this.maybeLength = maybeLength;
-    this.dict = dict;
     this.params = params;
   }
 

src/core/parser.js

@@ -765,11 +765,11 @@ class Parser {
       }
       if (name === "DCTDecode" || name === "DCT") {
         xrefStreamStats[StreamType.DCT] = true;
-        return new JpegStream(stream, maybeLength, stream.dict, params);
+        return new JpegStream(stream, maybeLength, params);
       }
       if (name === "JPXDecode" || name === "JPX") {
         xrefStreamStats[StreamType.JPX] = true;
-        return new JpxStream(stream, maybeLength, stream.dict, params);
+        return new JpxStream(stream, maybeLength, params);
       }
       if (name === "ASCII85Decode" || name === "A85") {
         xrefStreamStats[StreamType.A85] = true;
@@ -789,7 +789,7 @@ class Parser {
       }
       if (name === "JBIG2Decode") {
         xrefStreamStats[StreamType.JBIG] = true;
-        return new Jbig2Stream(stream, maybeLength, stream.dict, params);
+        return new Jbig2Stream(stream, maybeLength, params);
       }
       warn(`Filter "${name}" is not supported.`);
       return stream;