[wasm] Rework encoding of local declarations.

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 29 matching lines @@
         .addLocals({i32_count: 1})
         .addBody([kExprSetLocal, 1, kExprGetLocal, 0])
         .exportAs("main");
 
     var buffer = module.toBuffer(debug);
     var instance = _WASMEXP_.instantiateModule(buffer);
     assertEquals(19, instance.exports.main(19));
     assertEquals(27777, instance.exports.main(27777));
 })();
 
+(function LocalsTest2() {
+    // TODO(titzer): i64 only works on 64-bit platforms.
+    var types = [
+      {locals: {i32_count: 1}, type: kAstI32},
+//      {locals: {i64_count: 1}, type: kAstI64},
+      {locals: {f32_count: 1}, type: kAstF32},
+      {locals: {f64_count: 1}, type: kAstF64},
+    ];
+
+    for (p of types) {
+      var module = new WasmModuleBuilder();
+      module.addFunction(undefined, [p.type, p.type])
+        .addLocals(p.locals)
+        .addBody([kExprSetLocal, 1, kExprGetLocal, 0])
+        .exportAs("main");
+
+      var buffer = module.toBuffer(debug);
+      var instance = _WASMEXP_.instantiateModule(buffer);
+      assertEquals(19, instance.exports.main(19));
+      assertEquals(27777, instance.exports.main(27777));
+    }
+})();
+
 (function CallTest() {
     var module = new WasmModuleBuilder();
     module.addFunction("add", [kAstI32, kAstI32, kAstI32])
         .addBody([kExprI32Add, kExprGetLocal, 0, kExprGetLocal, 1]);
     module.addFunction("main", [kAstI32, kAstI32, kAstI32])
         .addBody([kExprCallFunction, 0, kExprGetLocal, 0, kExprGetLocal, 1])
         .exportAs("main");
 
     var instance = module.instantiate();
     assertEquals(44, instance.exports.main(11, 33));
@@ skipping 21 matching lines @@
     module.addMemory(1, 1, false);
     module.addFunction("load", [kAstI32, kAstI32])
         .addBody([kExprI32LoadMem, 0, kExprGetLocal, 0])
         .exportAs("load");
     module.addDataSegment(0, [9, 9, 9, 9], true);
 
     var buffer = module.toBuffer(debug);
     var instance = _WASMEXP_.instantiateModule(buffer);
     assertEquals(151587081, instance.exports.load(0));
 })();