remove extractMallocCallFromBitCast, since it was tailor maded for its sole user. Update GlobalOpt accordingly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158952 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index cca959b..ab58c41 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/lib/Transforms/IPO/GlobalOpt.cpp
@@ -1567,8 +1567,10 @@
       Instruction *Cast = new BitCastInst(Malloc, CI->getType(), "tmp", CI);
       CI->replaceAllUsesWith(Cast);
       CI->eraseFromParent();
-      CI = dyn_cast<BitCastInst>(Malloc) ?
-        extractMallocCallFromBitCast(Malloc) : cast<CallInst>(Malloc);
+      if (BitCastInst *BCI = dyn_cast<BitCastInst>(Malloc))
+        CI = cast<CallInst>(BCI->getOperand(0));
+      else
+      CI = cast<CallInst>(Malloc);
     }
 
     GVI = PerformHeapAllocSRoA(GV, CI, getMallocArraySize(CI, TD, true), TD);