[PATCH, AArch64] Remove unused types and variables for abi types

[Yufeng Zhang]

This patch removes unused types and variables claimed to handle abi 
types in aarch64.

OK for the trunk?
Thanks,
Yufeng

gcc/

        * config/aarch64/aarch64.h (enum arm_abi_type): Remove.
        (ARM_ABI_AAPCS64): Ditto.
        (arm_abi): Ditto.
        (ARM_DEFAULT_ABI): Ditto.diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index a08797b..7bdb1e2 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -521,12 +521,6 @@ typedef struct GTY (()) machine_function
 #endif
 
 
-/* Which ABI to use.  */
-enum arm_abi_type
-{
-  ARM_ABI_AAPCS64
-};
-
 enum arm_pcs
 {
   ARM_PCS_AAPCS64,             /* Base standard AAPCS for 64 bit.  */
@@ -534,11 +528,7 @@ enum arm_pcs
 };
 
 
-extern enum arm_abi_type arm_abi;
 extern enum arm_pcs arm_pcs_variant;
-#ifndef ARM_DEFAULT_ABI
-#define ARM_DEFAULT_ABI ARM_ABI_AAPCS64
-#endif
 
 #ifndef ARM_DEFAULT_PCS
 #define ARM_DEFAULT_PCS ARM_PCS_AAPCS64