codegen: fix duplicated params making malformed wasm

halves malformed wasm errors again!

test262: 51.07% (+0.02) | 🧪 48381 | 🤠 24709 (+11) | ❌ 6979 (+25) | 💀 15269 | 🏗️ 25 (-36) | 💥 329 | ⏰ 134 | 📝 936

compiler/codegen.js

@@ -3055,15 +3055,18 @@ const typeIsNotOneOf = (type, types, valtype = Valtype.i32) => {
   return out;
 };
 
-const allocVar = (scope, name, global = false, type = true) => {
+const allocVar = (scope, name, global = false, type = true, redecl = false) => {
   const target = global ? globals : scope.locals;
 
   // already declared
   if (Object.hasOwn(target, name)) {
-    // parser should catch this but sanity check anyway
-    // if (decl.kind !== 'var') return internalThrow(scope, 'SyntaxError', `Identifier '${unhackName(name)}' has already been declared`);
-
-    return target[name].idx;
+    if (redecl) {
+      // force change old local name(s)
+      target['#redecl_' + name + uniqId()] = target[name];
+      if (type) target['#redecl_' + name + '#type' + uniqId()] = target[name + '#type'];
+    } else {
+      return target[name].idx;
+    }
   }
 
   let idx = global ? globals['#ind']++ : scope.localInd++;
@@ -6515,7 +6518,7 @@ const generateFunc = (scope, decl, forceNoExpr = false) => {
         const { name, def, destr, type } = args[i];
 
         func.localInd = i * 2;
-        allocVar(func, name, false);
+        allocVar(func, name, false, true, true);
 
         func.localInd = localInd;
         if (type) {

package.json

@@ -1,7 +1,7 @@
 {
   "name": "porffor",
   "description": "a basic experimental wip aot optimizing js -> wasm engine/compiler/runtime in js",
-  "version": "0.50.19",
+  "version": "0.50.20",
   "author": "CanadaHonk",
   "license": "MIT",
   "scripts": {},

runner/index.js

@@ -1,6 +1,6 @@
 #!/usr/bin/env node
 import fs from 'node:fs';
-globalThis.version = '0.50.19';
+globalThis.version = '0.50.20';
 
 // deno compat
 if (typeof process === 'undefined' && typeof Deno !== 'undefined') {