Make TargetInstrInfo::isCopyInstr return true for regular COPY-instructions

..Move all target-dependent checks into new isCopyInstrImpl method.

This change allows us to treat MoveReg-type instructions and generic
COPY instruction in the same way

Differential Revision: https://reviews.llvm.org/D49913

llvm-svn: 341072
diff --git a/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp b/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
index 4c8f628..1b626ff 100644
--- a/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -935,9 +935,9 @@
     Mov->addRegisterKilled(SrcReg, TRI);
 }
 
-bool ARMBaseInstrInfo::isCopyInstr(const MachineInstr &MI,
-                                   const MachineOperand *&Src,
-                                   const MachineOperand *&Dest) const {
+bool ARMBaseInstrInfo::isCopyInstrImpl(const MachineInstr &MI,
+                                       const MachineOperand *&Src,
+                                       const MachineOperand *&Dest) const {
   // VMOVRRD is also a copy instruction but it requires
   // special way of handling. It is more complex copy version
   // and since that we are not considering it. For recognition