#476 SHGetFolderW declaration is at the wrong spot

[Jan Engelhardt]

New bug since 4.0 (present up to including 4.0.2):

In downstream packages, gcc emits:

   CC       master.o
 In file included from master.c:48:0:
 /usr/x86_64-w64-mingw32/sys-root/mingw/include/shlobj.h:37:3: error: unknown type name 'EXTERN_C'
    SHFOLDERAPI SHGetFolderPathW (HWND hwnd, int csidl, HANDLE hToken, DWORD dwFlags, LPWSTR pszPath);

SHLFOLDERAPI is defined to expand to something with EXTERN_C,
however, EXTERN_C is not defined at the time of SHGetFolderPathW
declaration.

[Jan Engelhardt]

patch provided.