[wasm] Support undefined indirect table entries, behind a flag.

test/mjsunit/wasm/default-func-call.js

 // Copyright 2015 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
+// Flags: --wasm-jit-prototype
 
 load("test/mjsunit/wasm/wasm-constants.js");
 load("test/mjsunit/wasm/wasm-module-builder.js");
 
 var module = (function () {
   var builder = new WasmModuleBuilder();
 
   var sig_index = builder.addType(kSig_i_ii);
+  builder.addPadFunctionTable(512);
   builder.addImport("add", sig_index);
   builder.addFunction("add", sig_index)
     .addBody([
       kExprGetLocal, 0, kExprGetLocal, 1, kExprCallImport, kArity2, 0
     ]);
   builder.addFunction("sub", sig_index)
     .addBody([
       kExprGetLocal, 0,             // --
       kExprGetLocal, 1,             // --
       kExprI32Sub,                  // --
@@ skipping 15 matching lines @@
 assertFalse(module === undefined);
 assertFalse(module === null);
 assertFalse(module === 0);
 assertEquals("object", typeof module.exports);
 assertEquals("function", typeof module.exports.main);
 
 assertEquals(5, module.exports.main(1, 12, 7));
 assertEquals(19, module.exports.main(0, 12, 7));
 
 assertTraps(kTrapFuncSigMismatch, "module.exports.main(2, 12, 33)");
-assertTraps(kTrapFuncInvalid, "module.exports.main(3, 12, 33)");
+assertTraps(kTrapFuncSigMismatch, "module.exports.main(4, 12, 33)");
+assertTraps(kTrapFuncSigMismatch, "module.exports.main(511, 12, 33)");
+assertTraps(kTrapFuncInvalid, "module.exports.main(512, 12, 33)");
+assertTraps(kTrapFuncInvalid, "module.exports.main(1025, 12, 33)");
+assertTraps(kTrapFuncInvalid, "module.exports.main(-1, 12, 33)");