Refactor ABI code in the PowerPC backend.

Make CalculateParameterAndLinkageAreaSize() Darwin-specific.
Remove SVR4 specific code from LowerCALL_Darwin() and LowerFORMAL_ARGUMENTS_Darwin().
Rename MachoABI to DarwinABI for consistency.
Rename ELF ABI to SVR4 ABI for consistency.
Factor out common call return lowering between the Darwin and SVR4 ABI.
Factor out common call lowering between the Darwin and SVR4 ABI.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74766 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCHazardRecognizers.cpp b/lib/Target/PowerPC/PPCHazardRecognizers.cpp
index e7658fc..ec3e757 100644
--- a/lib/Target/PowerPC/PPCHazardRecognizers.cpp
+++ b/lib/Target/PowerPC/PPCHazardRecognizers.cpp
@@ -159,7 +159,7 @@
   }
   
   // Do not allow MTCTR and BCTRL to be in the same dispatch group.
-  if (HasCTRSet && (Opcode == PPC::BCTRL_Macho || Opcode == PPC::BCTRL_ELF))
+  if (HasCTRSet && (Opcode == PPC::BCTRL_Darwin || Opcode == PPC::BCTRL_SVR4))
     return NoopHazard;
   
   // If this is a load following a store, make sure it's not to the same or