#include <winbase.h> is not enough for Visual C++ 2013, it errors:

1>C:\Program Files (x86)\Windows Kits\8.1\Include\um\minwinbase.h(46):
error C2146: syntax error : missing ';' before identifier 'nLength'
1>C:\Program Files (x86)\Windows Kits\8.1\Include\um\minwinbase.h(46):
error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
...

including <windows.h> is actually required.

llvm-svn: 221244