codegen: fix for without test or update crashing

test262: 11.23% (+0.06) | 🧪 49377 | 🤠 5547 (+34) | ❌ 1265 (+9) | 💀 8720 (+64) | 🧩 2481 (+3) | 💥 1436 (-115) | ⏰ 2 (+1) | 📝 29926 (+4)

compiler/codeGen.js

@@ -2315,17 +2315,18 @@ const generateFor = (scope, decl) => {
   out.push([ Opcodes.loop, Blocktype.void ]);
   depth.push('for');
 
-  out.push(...generate(scope, decl.test));
-  out.push(Opcodes.i32_to, [ Opcodes.if, Blocktype.void ]);
+  if (decl.test) out.push(...generate(scope, decl.test), Opcodes.i32_to);
+    else out.push(...number(1, Valtype.i32));
+
+  out.push([ Opcodes.if, Blocktype.void ]);
   depth.push('if');
 
   out.push([ Opcodes.block, Blocktype.void ]);
   depth.push('block');
   out.push(...generate(scope, decl.body));
   out.push([ Opcodes.end ]);
 
-  out.push(...generate(scope, decl.update));
-  depth.pop();
+  if (decl.update) out.push(...generate(scope, decl.update));
 
   out.push([ Opcodes.br, 1 ]);
   out.push([ Opcodes.end ], [ Opcodes.end ]);