[wasm] Rework encoding of local declarations.

test/mjsunit/wasm/stack.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");
 
 function testStack(func, check) {
-  var kBodySize = 2;
+  var kBodySize = 3;
   var kNameFunOffset = kHeaderSize + 22 + kBodySize + 1;
   var kNameMainOffset = kNameFunOffset + 4;
 
   var ffi = new Object();
   ffi.fun = func;
 
   var data = bytesWithHeader(
       // signatures
       kDeclSignatures, 1,  //  --
       0, kAstStmt,         // () -> void
       // -- foreign function
       kDeclFunctions, 2,                        //  --
       kDeclFunctionName | kDeclFunctionImport,  // --
       0, 0,                                     //  --
       kNameFunOffset, 0, 0, 0,                  // name offset
       // -- main function
       kDeclFunctionName | kDeclFunctionExport,  // --
       0, 0,                                     //  --
       kNameMainOffset, 0, 0, 0,                 // name offset
       kBodySize, 0,
       // main body
+      kDeclNoLocals,
       kExprCallFunction, 0,  // --
       // names
       kDeclEnd,              //  --
       'f', 'u', 'n', 0,      //  --
       'm', 'a', 'i', 'n', 0  //  --
       );
 
   var module = _WASMEXP_.instantiateModule(data, ffi);
 
   assertEquals("function", typeof module.main);
@@ skipping 12 matching lines @@
   var e = new Error();
   stack = e.stack;
 }
 
 function check_STACK() {
   assertEquals(expected, stripPath(stack));
 }
 
 var expected = "Error\n" +
     // The line numbers below will change as this test gains / loses lines..
-    "    at STACK (stack.js:54:11)\n" +  // --
+    "    at STACK (stack.js:55:11)\n" +  // --
     "    at <WASM> (<anonymous>)\n" +  // --
     "    at <WASM> (<anonymous>)\n" +  // --
     "    at <WASM> (<anonymous>)\n" +  // --
-    "    at testStack (stack.js:43:10)\n" +
+    "    at testStack (stack.js:44:10)\n" +
     // TODO(jfb) Add WebAssembly stack here.
-    "    at stack.js:72:1";
+    "    at stack.js:73:1";
 
 testStack(STACK, check_STACK);