[x64] Do not compact constants with attached reloc info.

test/mjsunit/regress/wasm/regression-684407.js

+// Copyright 2017 the V8 project authors. All rights reserved.

[titzer, 2017/01/26 10:48:07]

Hmm, I don't think we should necessarily have a WASM-level test for this, but
instead an assembler-level test.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+load("test/mjsunit/wasm/wasm-constants.js");
+load("test/mjsunit/wasm/wasm-module-builder.js");
+
+(function() {
+  var builder = new WasmModuleBuilder();
+  builder.addMemory(16, 32, false);
+  builder.addFunction("test", kSig_i_iii)
+    .addBodyWithEnd([
+// body:
+kExprGetLocal, 0x00,
+kExprGrowMemory, 0x00,
+kExprGetLocal, 0x00,
+kExprGrowMemory, 0x00,
+kExprGetLocal, 0x01,
+kExprGrowMemory, 0x00,
+kExprGetLocal, 0x01,
+kExprGrowMemory, 0x00,
+kExprGetLocal, 0x00,
+kExprGrowMemory, 0x00,
+kExprGetLocal, 0x01,
+kExprGrowMemory, 0x00,
+kExprGetLocal, 0x01,
+kExprGrowMemory, 0x00,
+kExprGetLocal, 0x00,
+kExprGrowMemory, 0x00,
+kExprGetLocal, 0x00,
+kExprGrowMemory, 0x00,
+kExprGetLocal, 0x01,
+kExprGrowMemory, 0x00,
+kExprI32StoreMem16, 0x00, 0xff, 0xff, 0x3f,
+kExprUnreachable,
+kExprEnd,   // @90
+            ])
+            .exportFunc();
+  var module = builder.instantiate();
+  assertTraps(kTrapUnreachable, () => {module.exports.test(1, 2, 3)});
+})();