[wasm] mjsunit support for I32 globals and test

test/mjsunit/wasm/wasm-module-builder.js

Index: test/mjsunit/wasm/wasm-module-builder.js
diff --git a/test/mjsunit/wasm/wasm-module-builder.js b/test/mjsunit/wasm/wasm-module-builder.js
index fecd164b56b00430af074f7f55da9b586484f259..f0cf9d18d3570a5a6e161074f738609ff6d208b1 100644
--- a/test/mjsunit/wasm/wasm-module-builder.js
+++ b/test/mjsunit/wasm/wasm-module-builder.js
@@ -104,6 +104,7 @@ class WasmModuleBuilder {
   constructor() {
     this.types = [];
     this.imports = [];
+    this.globals = [];
     this.functions = [];
     this.exports = [];
     this.table = [];
@@ -138,6 +139,11 @@ class WasmModuleBuilder {
     return this.types.length - 1;
   }
 
+  addGlobal(local_type) {
+    this.globals.push(local_type);
+    return this.globals.length - 1;
+  }
+
   addFunction(name, type) {
     let type_index = (typeof type) == "number" ? type : this.addType(type);
     let func = new WasmFunctionBuilder(name, type_index);
@@ -192,6 +198,18 @@ class WasmModuleBuilder {
       });
     }
 
+    if (wasm.globals.length > 0) {
+      if (debug) print ("emitting globals @ " + binary.length);
+      binary.emit_section(kDeclGlobals, section => {
+        section.emit_varint(wasm.globals.length);
+        for (let global_type of wasm.globals) {
+          section.emit_varint(0);  // length of global name
+          section.emit_u8(global_type);
+          section.emit_u8(false);  // we do not support exported globals
+        }
+      });
+    }
+
     // Add imports section
     if (wasm.imports.length > 0) {
       if (debug) print("emitting imports @ " + binary.length);