Re-factor the BaseException.name handling, and clean-up some code

Once we're finally able to get rid of SystemJS, which is unfortunately still blocked on [bug 1247687](https://bugzilla.mozilla.org/show_bug.cgi?id=1247687), we might also want to clean-up (or even completely remove) the `BaseException` abstraction and simply extend `Error` directly instead.

At that point we'd need to (explicitly) set the `name` on each class anyway, so this patch is essentially preparing for future clean-up. Furthermore, after the `BaseException` abstraction was added there's been *multiple* issues filed about third-party minification breaking our code since `this.constructor.name` is not guaranteed to always do what you intended.

While hard-coding the strings indeed feels quite unfortunate, it's likely the "best" solution to avoid the problem described above.

src/core/core_utils.js

@@ -52,17 +52,29 @@ function getArrayLookupTableFactory(initializer) {
 
 class MissingDataException extends BaseException {
   constructor(begin, end) {
-    super(`Missing data [${begin}, ${end})`);
+    super(`Missing data [${begin}, ${end})`, "MissingDataException");
     this.begin = begin;
     this.end = end;
   }
 }
 
-class ParserEOFException extends BaseException {}
+class ParserEOFException extends BaseException {
+  constructor(msg) {
+    super(msg, "ParserEOFException");
+  }
+}
 
-class XRefEntryException extends BaseException {}
+class XRefEntryException extends BaseException {
+  constructor(msg) {
+    super(msg, "XRefEntryException");
+  }
+}
 
-class XRefParseException extends BaseException {}
+class XRefParseException extends BaseException {
+  constructor(msg) {
+    super(msg, "XRefParseException");
+  }
+}
 
 /**
  * Get the value of an inheritable property.

src/core/jbig2.js

@@ -20,7 +20,7 @@ import { CCITTFaxDecoder } from "./ccitt.js";
 
 class Jbig2Error extends BaseException {
   constructor(msg) {
-    super(`JBIG2 error: ${msg}`);
+    super(`JBIG2 error: ${msg}`, "Jbig2Error");
   }
 }
 

src/core/jpg.js

@@ -18,18 +18,22 @@ import { readUint16 } from "./core_utils.js";
 
 class JpegError extends BaseException {
   constructor(msg) {
-    super(`JPEG error: ${msg}`);
+    super(`JPEG error: ${msg}`, "JpegError");
   }
 }
 
 class DNLMarkerError extends BaseException {
   constructor(message, scanLines) {
-    super(message);
+    super(message, "DNLMarkerError");
     this.scanLines = scanLines;
   }
 }
 
-class EOIMarkerError extends BaseException {}
+class EOIMarkerError extends BaseException {
+  constructor(msg) {
+    super(msg, "EOIMarkerError");
+  }
+}
 
 /**
  * This code was forked from https://github.com/notmasteryet/jpgjs.

src/core/jpx.js

@@ -19,7 +19,7 @@ import { ArithmeticDecoder } from "./arithmetic_decoder.js";
 
 class JpxError extends BaseException {
   constructor(msg) {
-    super(`JPX error: ${msg}`);
+    super(`JPX error: ${msg}`, "JpxError");
   }
 }