Explicitly convert to double to suppress Visual C++ 2008 build error C2668 pow is ambiguous call to overloaded function

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85478 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp
index 0982345..707a9ee 100644
--- a/lib/Analysis/MemoryBuiltins.cpp
+++ b/lib/Analysis/MemoryBuiltins.cpp
@@ -159,7 +159,7 @@
       ConstantInt* Op1Int = dyn_cast<ConstantInt>(Op1);
       if (!Op1Int) return NULL;
       Value* Op1Pow = ConstantInt::get(Op1->getType(),
-                                       pow(2, Op1Int->getZExtValue()));
+                                       pow((double) 2, (double) Op1Int->getZExtValue()));
       if (Op0 == ElementSize || (FoldedElementSize && Op0 == FoldedElementSize))
         // ArraySize << log2(ElementSize)
         return Op1Pow;