Fix FastAccessorToSmi CCTest to use ptr type

The generated FastAccessorAssembler uses IntPtr Load Op to load
from &flags. Therefore, flags should be a pointer type. This fixes
big endian issue.

R=peterssen@google.com, vogelheim@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2266403004
Cr-Commit-Position: refs/heads/master@{#38873}

test/cctest/test-api-fast-accessor-builder.cc

@@ -428,7 +428,7 @@ TEST(FastAccessorToSmi) {
   // Create an instance.
   v8::Local<v8::Object> obj = foo->NewInstance(env.local()).ToLocalChecked();
 
-  uint32_t flags;
+  uintptr_t flags;
   obj->SetAlignedPointerInInternalField(0, &flags);
   CHECK(env->Global()->Set(env.local(), v8_str("obj"), obj).FromJust());