Fix warnings on Win64.

src/x64/fast-codegen-x64.cc

Index: src/x64/fast-codegen-x64.cc
diff --git a/src/x64/fast-codegen-x64.cc b/src/x64/fast-codegen-x64.cc
index cfd8c4fae3f9613f04154ee2eac7f49781f3bb5d..04e523921383c87e306c1340144599ad48a980ef 100644
--- a/src/x64/fast-codegen-x64.cc
+++ b/src/x64/fast-codegen-x64.cc
@@ -148,7 +148,7 @@ void FastCodeGenerator::EmitReturnSequence(int position) {
     }
     // Check that the size of the code used for returning matches what is
     // expected by the debugger.
-    ASSERT_EQ(Debug::Debug::kX64JSReturnSequenceLength,
+    ASSERT_EQ(Debug::kX64JSReturnSequenceLength,
             masm_->SizeOfCodeGeneratedSince(&check_exit_codesize));
 #endif
   }