Fix Windows build by including CGFunctionInfo.h.

CodeGenTypes.h instantiates llvm::FoldingSet<> with CGFunctionInfo,
and VC++ doesn't like the static_cast from FoldingSetImpl::Node* to
CGFunctionInfo* since it hasn't seen the definition of CGFunctionInfo
and that it inherits from FoldingSetImpl::Node.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@193722 91177308-0d34-0410-b5e6-96231b3b80d8