Change an output parameter of Maybe<T>::To() from a reference to a pointer

This is a follow-up fix for https://codereview.chromium.org/2194793003/

BUG=

Review-Url: https://codereview.chromium.org/2205203002
Cr-Commit-Position: refs/heads/master@{#38305}

include/v8.h

@@ -6916,8 +6916,8 @@ class Maybe {
   // Will crash if the Maybe<> is nothing.
   V8_INLINE T ToChecked() const { return FromJust(); }
 
-  V8_WARN_UNUSED_RESULT V8_INLINE bool To(T& out) const {
-    if (V8_LIKELY(IsJust())) out = value_;
+  V8_WARN_UNUSED_RESULT V8_INLINE bool To(T* out) const {
+    if (V8_LIKELY(IsJust())) *out = value_;
     return IsJust();
   }
 

test/cctest/test-api.cc

@@ -335,7 +335,7 @@ THREADED_TEST(Access) {
 
   CHECK(obj->Set(env.local(), v8_str("foo"), bar_str).ToChecked());
   bool result;
-  CHECK(obj->Set(env.local(), v8_str("foo"), bar_str).To(result));
+  CHECK(obj->Set(env.local(), v8_str("foo"), bar_str).To(&result));
   CHECK(result);
 }