_mingw.h: Added _inline macro.

git-svn-id: svn+ssh://svn.code.sf.net/p/mingw-w64/code/trunk@5784 4407c894-4637-0410-b4f5-ada5f102cad1
diff --git a/mingw-w64-headers/crt/_mingw.h.in b/mingw-w64-headers/crt/_mingw.h.in
index d1f10c7..7a07fd6 100644
--- a/mingw-w64-headers/crt/_mingw.h.in
+++ b/mingw-w64-headers/crt/_mingw.h.in
@@ -79,6 +79,10 @@
 #define USE___UUIDOF	0
 #endif
 
+#if !defined(_MSC_VER) && !defined(_inline)
+#define _inline __inline
+#endif
+
 #ifdef __cplusplus
 # define __CRT_INLINE inline
 #elif defined(_MSC_VER)