Split IMPLICIT_DEF into IMPLICIT_DEF_GPR and IMPLICIT_DEF_FP, so that the

instructions take a consistent reg class.  Implement ISD::UNDEF in the dag->dag
selector to generate this, fixing UnitTests/2003-07-06-IntOverflow.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23028 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/PowerPC/PPCBranchSelector.cpp

@@ -40,7 +40,8 @@ namespace {
         // minor pessimization that saves us from having to worry about
         // keeping the offsets up to date later when we emit long branch glue.
         return 12;
-      case PPC::IMPLICIT_DEF: // no asm emitted
+      case PPC::IMPLICIT_DEF_GPR: // no asm emitted
+      case PPC::IMPLICIT_DEF_FP: // no asm emitted
         return 0;
       default:
         break;