[wasm] Encode immediates to Load and Store as varint.

test/mjsunit/wasm/test-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.
 
 // Flags: --expose-wasm
 
 load('test/mjsunit/wasm/wasm-constants.js');
 load('test/mjsunit/wasm/wasm-module-builder.js');
 
 var debug = false;
@@ skipping 85 matching lines @@
     var instance = module.instantiate();
     assertEquals(44, instance.exports.main(0, 11, 33));
     assertEquals(7777, instance.exports.main(0, 2222, 5555));
     assertThrows(function() { instance.exports.main(1, 1, 1); });
 })();
 
 (function DataSegmentTest() {
     var module = new WasmModuleBuilder();
     module.addMemory(1, 1, false);
     module.addFunction("load", [kAstI32, kAstI32])
-        .addBody([kExprI32LoadMem, 0, kExprGetLocal, 0])
+        .addBody([kExprI32LoadMem, 0, 0, kExprGetLocal, 0])
         .exportAs("load");
     module.addDataSegment(0, [9, 9, 9, 9], true);
 
     var buffer = module.toBuffer(debug);
     var instance = Wasm.instantiateModule(buffer);
     assertEquals(151587081, instance.exports.load(0));
 })();
 
 
 (function BasicTestWithUint8Array() {
@@ skipping 27 matching lines @@
     var index = module.addImportWithModule("mod", "print", [kAstStmt, kAstI32]);
     module.addFunction("foo", [kAstStmt])
         .addBody([kExprCallImport, index, kExprI8Const, 19])
         .exportAs("main");
 
     var buffer = module.toBuffer(debug);
     var instance = Wasm.instantiateModule(buffer, {mod: {print: print}});
     print("should print 19! ");
     instance.exports.main();
 })();