Convert EXTRACT_SUBREG to COPY when emitting machine instrs.

EXTRACT_SUBREG no longer appears as a machine instruction. Use COPY instead.

Add isCopy() checks in many places using isMoveInstr() and isExtractSubreg().
The isMoveInstr hook will be removed later.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107879 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/ProcessImplicitDefs.cpp b/lib/CodeGen/ProcessImplicitDefs.cpp
index 2caef08..ca4c477 100644
--- a/lib/CodeGen/ProcessImplicitDefs.cpp
+++ b/lib/CodeGen/ProcessImplicitDefs.cpp
@@ -50,8 +50,7 @@
     return true;
 
   switch(OpIdx) {
-    case 1: return (MI->isExtractSubreg() || MI->isCopy()) &&
-                   MI->getOperand(0).getSubReg() == 0;
+    case 1: return MI->isCopy() && MI->getOperand(0).getSubReg() == 0;
     case 2: return MI->isSubregToReg() && MI->getOperand(0).getSubReg() == 0;
     default: return false;
   }