[wasm] Use the JavaScript WasmModuleBuilder utility in JS tests.

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

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 function StringRef(string) {
     this.pos = -1;
     this.string = string;
 }
 
 function DataRef(data) {
     this.pos = -1;
     this.data = data;
 }
 
 function WasmFunctionBuilder(name, sig_index) {
     this.name = name;
     this.sig_index = sig_index;
     this.exports = [];
 }
 
 WasmFunctionBuilder.prototype.exportAs = function(name) {
     this.exports.push(name);
     return this;
 }
 
+WasmFunctionBuilder.prototype.exportFunc = function() {
+  this.exports.push(this.name);
+  return this;
+}
+
 WasmFunctionBuilder.prototype.addBody = function(body) {
     this.body = body;
     return this;
 }
 
 WasmFunctionBuilder.prototype.addLocals = function(locals) {
     this.locals = locals;
     return this;
 }
 
 function WasmModuleBuilder() {
     this.signatures = [];
     this.imports = [];
     this.functions = [];
     this.exports = [];
     this.function_table = [];
     this.data_segments = [];
+    this.explicit = [];
     return this;
 }
 
+WasmModuleBuilder.prototype.addStart = function(start_index) {
+    this.start_index = start_index;
+}
+
 WasmModuleBuilder.prototype.addMemory = function(min, max, exp) {
     this.memory = {min: min, max: max, exp: exp};
     return this;
 }
 
+WasmModuleBuilder.prototype.addExplicitSection = function(bytes) {
+  this.explicit.push(bytes);
+  return this;
+}
+
 // Add a signature; format is [rettype, param0, param1, ...]
 WasmModuleBuilder.prototype.addSignature = function(sig) {
     // TODO: canonicalize signatures?
     this.signatures.push(sig);
     return this.signatures.length - 1;
 }
 
 WasmModuleBuilder.prototype.addFunction = function(name, sig) {
     var sig_index = (typeof sig) == "number" ? sig : this.addSignature(sig);
     var func = new WasmFunctionBuilder(name, sig_index);
@@ skipping 131 matching lines @@
             }
             emit_u16(bytes, func.body.length);
             for (var i = 0; i < func.body.length; i++) {
                 emit_u8(bytes, func.body[i]);
             }
 
             index++;
         }
     }
 
+    // Add start function section.
+    if (this.start_index != undefined) {
+        if (debug) print("emitting start function @ " + bytes.length);
+      emit_u8(bytes, kDeclStartFunction);
+      emit_varint(bytes, this.start_index);
+    }
+
     if (this.function_table.length > 0) {
         if (debug) print("emitting function table @ " + bytes.length);
         emit_u8(bytes, kDeclFunctionTable);
         emit_varint(bytes, this.function_table.length);
         for (index of this.function_table) {
             emit_u16(bytes, index);
         }
     }
 
     if (exports > 0) {
@@ skipping 13 matching lines @@
         emit_u8(bytes, kDeclDataSegments);
         emit_varint(bytes, this.data_segments.length);
         for (seg of this.data_segments) {
             emit_u32(bytes, seg.addr);
             emit_data_ref(bytes, seg.data);
             emit_u32(bytes, seg.data.length);
             emit_u8(bytes, seg.init ? 1 : 0);
         }
     }
 
+    // Emit any explicitly added sections
+    for (exp of this.explicit) {
+        if (debug) print("emitting explicit @ " + bytes.length);
+        for (var i = 0; i < exp.length; i++) {
+            emit_u8(bytes, exp[i]);
+        }
+    }
+
     // End the module.
     if (debug) print("emitting end @ " + bytes.length);
     emit_u8(bytes, kDeclEnd);
 
     // Collect references and canonicalize strings.
     var strings = new Object();
     var data_segments = [];
     var count = 0;
     for (var i = 0; i < bytes.length; i++) {
         var b = bytes[i];
@@ skipping 53 matching lines @@
     var buffer = new ArrayBuffer(bytes.length);
     var view = new Uint8Array(buffer);
     for (var i = 0; i < bytes.length; i++) {
         var val = bytes[i];
         if ((typeof val) == "string") val = val.charCodeAt(0);
         view[i] = val | 0;
     }
     return buffer;
 }
 
-WasmModuleBuilder.prototype.instantiate = function(ffi) {
+WasmModuleBuilder.prototype.instantiate = function(ffi, memory) {
     var buffer = this.toBuffer();
-    return _WASMEXP_.instantiateModule(buffer, ffi);
+    if (memory != undefined) {
+      return _WASMEXP_.instantiateModule(buffer, ffi, memory);
+    } else {
+      return _WASMEXP_.instantiateModule(buffer, ffi);
+    }
 }