Silence static analyzer getAs<VectorType> null dereference warnings. NFCI.

The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<VectorType> directly and if not assert will fire for us.

llvm-svn: 373478
diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index 77ec54d..4676be4 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -1657,8 +1657,8 @@
   if (SrcTy == DstTy)
     return Src;
 
-  QualType SrcEltType = SrcType->getAs<VectorType>()->getElementType(),
-           DstEltType = DstType->getAs<VectorType>()->getElementType();
+  QualType SrcEltType = SrcType->castAs<VectorType>()->getElementType(),
+           DstEltType = DstType->castAs<VectorType>()->getElementType();
 
   assert(SrcTy->isVectorTy() &&
          "ConvertVector source IR type must be a vector");
@@ -3745,7 +3745,7 @@
       Value *FirstVecArg = LHS,
             *SecondVecArg = RHS;
 
-      QualType ElTy = LHSTy->getAs<VectorType>()->getElementType();
+      QualType ElTy = LHSTy->castAs<VectorType>()->getElementType();
       const BuiltinType *BTy = ElTy->getAs<BuiltinType>();
       BuiltinType::Kind ElementKind = BTy->getKind();