Fix Windows build problems.

GCC's visibility attribute is for ELF systems, so undef INTERNAL
GCC's fastcall attribute interferes with __stdcall so undef FASTCALL

src/glx/x11/indirect_size.c

@@ -47,7 +47,6 @@
 #    define INTERNAL
 #  endif
 
-
 #ifdef HAVE_ALIAS
 #  define ALIAS2(from,to) \
     INTERNAL PURE FASTCALL GLint __gl ## from ## _size( GLenum e ) \
@@ -59,6 +58,13 @@
     { return __gl ## to ## _size( e ); }
 #endif
 
+#  if defined(__CYGWIN__) || defined(WIN32)
+#    undef FASTCALL
+#    define FASTCALL
+#    undef HAVE_ALIAS
+#    undef INTERNAL
+#    define INTERNAL
+#  endif
 
 INTERNAL PURE FASTCALL GLint
 __glCallLists_size( GLenum e )

src/glx/x11/indirect_size.h

@@ -54,6 +54,13 @@
 #    define INTERNAL
 #  endif
 
+#  if defined(__CYGWIN__) || defined(WIN32)
+#    undef FASTCALL
+#    define FASTCALL
+#    undef INTERNAL
+#    define INTERNAL
+#  endif
+
 extern INTERNAL PURE FASTCALL GLint __glCallLists_size(GLenum);
 extern INTERNAL PURE FASTCALL GLint __glFogfv_size(GLenum);
 extern INTERNAL PURE FASTCALL GLint __glFogiv_size(GLenum);