Fix gcc-4.6 warnings.

test/cctest/test-compiler.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 252 matching lines @@
 
 TEST(UncaughtThrow) {
   InitializeVM();
   v8::HandleScope scope;
 
   const char* source = "throw 42;";
   Handle<JSFunction> fun = Compile(source);
   CHECK(!fun.is_null());
   bool has_pending_exception;
   Handle<JSObject> global(Isolate::Current()->context()->global());
-  Handle<Object> result =
-      Execution::Call(fun, global, 0, NULL, &has_pending_exception);
+  Handle<Object> result(
+      Execution::Call(fun, global, 0, NULL, &has_pending_exception));
   CHECK(has_pending_exception);
   CHECK_EQ(42.0, Isolate::Current()->pending_exception()->
            ToObjectChecked()->Number());
 }
 
 
 // Tests calling a builtin function from C/C++ code, and the builtin function
 // performs GC. It creates a stack frame looks like following:
 //   | C (PerformGC) |
 //   |   JS-to-C     |
@@ skipping 112 matching lines @@
   CompileRun("function f() { a = 12345678 }; f();");
   CheckCodeForUnsafeLiteral(GetJSFunction(env->Global(), "f"));
   CompileRun("function f(x) { a = 12345678 + x}; f(1);");
   CheckCodeForUnsafeLiteral(GetJSFunction(env->Global(), "f"));
   CompileRun("function f(x) { var arguments = 1; x += 12345678}; f(1);");
   CheckCodeForUnsafeLiteral(GetJSFunction(env->Global(), "f"));
   CompileRun("function f(x) { var arguments = 1; x = 12345678}; f(1);");
   CheckCodeForUnsafeLiteral(GetJSFunction(env->Global(), "f"));
 }
 #endif