Split TailDuplicatePass into pre- and post-RA variant; NFC

Split TailDuplicatePass into EarlyTailDuplicate and TailDuplicate. This
avoids playing games with fake pass IDs and using MRI::isSSA() to
determine pre-/post-RA state.

llvm-svn: 322926
diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp
index 392f41a..e59ada5 100644
--- a/llvm/lib/CodeGen/TargetPassConfig.cpp
+++ b/llvm/lib/CodeGen/TargetPassConfig.cpp
@@ -226,7 +226,7 @@
   if (StandardID == &TailDuplicateID)
     return applyDisable(TargetID, DisableTailDuplicate);
 
-  if (StandardID == &TargetPassConfig::EarlyTailDuplicateID)
+  if (StandardID == &EarlyTailDuplicateID)
     return applyDisable(TargetID, DisableEarlyTailDup);
 
   if (StandardID == &MachineBlockPlacementID)
@@ -268,7 +268,6 @@
 char TargetPassConfig::ID = 0;
 
 // Pseudo Pass IDs.
-char TargetPassConfig::EarlyTailDuplicateID = 0;
 char TargetPassConfig::PostRAMachineLICMID = 0;
 
 namespace {
@@ -367,7 +366,6 @@
   initializeAAResultsWrapperPassPass(*PassRegistry::getPassRegistry());
 
   // Substitute Pseudo Pass IDs for real ones.
-  substitutePass(&EarlyTailDuplicateID, &TailDuplicateID);
   substitutePass(&PostRAMachineLICMID, &MachineLICMID);
 
   if (StringRef(PrintMachineInstrs.getValue()).equals(""))