Rename A64 port to ARM64 port

src/arm64/codegen-arm64.h

Index: src/arm64/codegen-arm64.h
diff --git a/src/a64/codegen-a64.h b/src/arm64/codegen-arm64.h
similarity index 96%
rename from src/a64/codegen-a64.h
rename to src/arm64/codegen-arm64.h
index 1bb9661f0b4b70d9e35d3a7f73186898063ac0c3..4d8a9a85a7c1b1a185c418360a341cd9ee54e9a5 100644
--- a/src/a64/codegen-a64.h
+++ b/src/arm64/codegen-arm64.h
@@ -25,8 +25,8 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef V8_A64_CODEGEN_A64_H_
-#define V8_A64_CODEGEN_A64_H_
+#ifndef V8_ARM64_CODEGEN_ARM64_H_
+#define V8_ARM64_CODEGEN_ARM64_H_
 
 #include "ast.h"
 #include "ic-inl.h"
@@ -68,4 +68,4 @@ class MathExpGenerator : public AllStatic {
 
 } }  // namespace v8::internal
 
-#endif  // V8_A64_CODEGEN_A64_H_
+#endif  // V8_ARM64_CODEGEN_ARM64_H_