headers: crt: disable getpid in UWP builds

It is not allowed.

It was already disabled in process.h from 7c2e0a371f0f631513611988688f0a6b19ea9731

https://docs.microsoft.com/en-us/cpp/cppcx/crt-functions-not-supported-in-universal-windows-platform-apps

Signed-off-by: Liu Hao <lh_mouse@126.com>

mingw-w64-headers/crt/unistd.h

diff --git a/mingw-w64-headers/crt/unistd.h b/mingw-w64-headers/crt/unistd.h
index ae3f68c..05512c5 100644
--- a/mingw-w64-headers/crt/unistd.h
+++ b/mingw-w64-headers/crt/unistd.h
@@ -93,10 +93,12 @@
   void __cdecl swab(char *_Buf1,char *_Buf2,int _SizeInBytes) __MINGW_ATTRIB_DEPRECATED_MSVC2005;
 #endif
 
+#ifdef _CRT_USE_WINAPI_FAMILY_DESKTOP_APP
 #ifndef _CRT_GETPID_DEFINED
 #define _CRT_GETPID_DEFINED /* Also in process.h */
   int __cdecl getpid(void) __MINGW_ATTRIB_DEPRECATED_MSVC2005;
 #endif
+#endif /* _CRT_USE_WINAPI_FAMILY_DESKTOP_APP */
 
 #ifdef __cplusplus
 }