[arm load/store optimizer] When trying to merge a base update load/store, make
sure the base register and would-be writeback register don't conflict for
stores.  This was already being done for loads.

Unfortunately, it is rather difficult to create a test case for this issue.  It
was exposed in 450.soplex at LTO and requires unlucky register allocation.
<rdar://13394908>

llvm-svn: 177874
diff --git a/llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp b/llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
index 98bd6c1..e4e683c 100644
--- a/llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
+++ b/llvm/lib/Target/ARM/ARMLoadStoreOptimizer.cpp
@@ -865,7 +865,7 @@
   bool isLd = isi32Load(Opcode) || Opcode == ARM::VLDRS || Opcode == ARM::VLDRD;
   // Can't do the merge if the destination register is the same as the would-be
   // writeback register.
-  if (isLd && MI->getOperand(0).getReg() == Base)
+  if (MI->getOperand(0).getReg() == Base)
     return false;
 
   unsigned PredReg = 0;