eliminate some VC++ warnings, patch contributed by Hartmut Kaiser

llvm-svn: 41692
diff --git a/clang/CodeGen/CodeGenFunction.cpp b/clang/CodeGen/CodeGenFunction.cpp
index 389bd05..d540ea7a 100644
--- a/clang/CodeGen/CodeGenFunction.cpp
+++ b/clang/CodeGen/CodeGenFunction.cpp
@@ -51,9 +51,9 @@
 
 void CodeGenFunction::GenerateCode(const FunctionDecl *FD) {
   LLVMIntTy = ConvertType(getContext().IntTy);
-  LLVMPointerWidth =
+  LLVMPointerWidth = static_cast<unsigned>(
     getContext().getTypeSize(getContext().getPointerType(getContext().VoidTy),
-                             SourceLocation());
+                             SourceLocation()));
   
   CurFn = cast<llvm::Function>(CGM.GetAddrOfGlobalDecl(FD));
   CurFuncDecl = FD;