x86_64: TargetReg update for x86

Also includes changes in common code. Elimination of use of TargetReg
with one parameter and direct access to special target registers.

Change-Id: Ied2c1f87d4d1e4345248afe74bca40487a46a371
Signed-off-by: Serguei Katkov <serguei.i.katkov@intel.com>
Signed-off-by: Chao-ying Fu <chao-ying.fu@intel.com>
diff --git a/compiler/dex/quick/arm64/codegen_arm64.h b/compiler/dex/quick/arm64/codegen_arm64.h
index 7db6ab6..8692c6c 100644
--- a/compiler/dex/quick/arm64/codegen_arm64.h
+++ b/compiler/dex/quick/arm64/codegen_arm64.h
@@ -110,6 +110,10 @@
       RegStorage reg = TargetReg(symbolic_reg);
       return (reg.Is64Bit() ? reg : As64BitReg(reg));
     }
+    RegStorage TargetPtrReg(SpecialTargetRegister symbolic_reg) OVERRIDE {
+      RegStorage reg = TargetReg(symbolic_reg);
+      return (reg.Is64Bit() ? reg : As64BitReg(reg));
+    }
     RegStorage GetArgMappingToPhysicalReg(int arg_num);
     RegLocation GetReturnAlt();
     RegLocation GetReturnWideAlt();