[api-minor] Rewrite the ps lexer & parser and add a small Wasm compiler

The main goal is to remove the eval-based interpreter.
In order to have some good performances, the new parser performs some optimizations
on the AST (similar to the ones in the previous implementation),
and the Wasm compiler generates code for the optimized AST.
For now, in case of errors or unsupported features, the Wasm compiler returns null
and the old interpreter is used as a fallback.
Few things are still missing:
 - a wasm-based interpreter using a stack (in case the ps code isn't stack-free);
 - a better js implementation in case of disabled wasm.

 but they will be added in follow-up patches.

Author: calixteman

src/core/function.js

@@ -21,18 +21,30 @@ import {
   MathClamp,
   shadow,
   unreachable,
+  warn,
 } from "../shared/util.js";
 import { PostScriptLexer, PostScriptParser } from "./ps_parser.js";
 import { BaseStream } from "./base_stream.js";
+import { buildPostScriptWasmFunction } from "./postscript/wasm_compiler.js";
 import { isNumberArray } from "./core_utils.js";
 import { LocalFunctionCache } from "./image_utils.js";
 
 class PDFFunctionFactory {
+  static #useWasm = true;
+
+  static setOptions({ useWasm }) {
+    PDFFunctionFactory.#useWasm = useWasm;
+  }
+
   constructor({ xref, isEvalSupported = true }) {
     this.xref = xref;
     this.isEvalSupported = isEvalSupported !== false;
   }
 
+  get useWasm() {
+    return PDFFunctionFactory.#useWasm;
+  }
+
   create(fn, parseArray = false) {
     let fnRef, parsedFn;
 
@@ -358,6 +370,24 @@ class PDFFunction {
       throw new FormatError("No range.");
     }
 
+    if (factory.useWasm) {
+      try {
+        const wasmFn = buildPostScriptWasmFunction(
+          fn.getString(),
+          domain,
+          range
+        );
+        if (wasmFn) {
+          return wasmFn; // (src, srcOffset, dest, destOffset) → void
+        }
+      } catch {
+        // Fall through to the existing interpreter-based path.
+      }
+    }
+
+    warn("Unable to compile PS function, using interpreter");
+    fn.reset();
+
     const lexer = new PostScriptLexer(fn);
     const parser = new PostScriptParser(lexer);
     const code = parser.parse();

src/core/pdf_manager.js

@@ -28,6 +28,7 @@ import { JpxImage } from "./jpx.js";
 import { MissingDataException } from "./core_utils.js";
 import { OperatorList } from "./operator_list.js";
 import { PDFDocument } from "./document.js";
+import { PDFFunctionFactory } from "./function.js";
 import { Stream } from "./stream.js";
 
 function parseDocBaseUrl(url) {
@@ -97,6 +98,7 @@ class BasePdfManager {
     IccColorSpace.setOptions(options);
     CmykICCBasedCS.setOptions(options);
     JBig2CCITTFaxWasmImage.setOptions(options);
+    PDFFunctionFactory.setOptions(options);
   }
 
   get docId() {