Fixes error about duplicated typedefs (also in glext.h) reported on
NetBSD 6.1
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=70546
Tested-by: Vinson Lee <vlee@freedesktop.org>
GLAPI void GLAPIENTRY glGetSeparableFilter( GLenum target, GLenum format,
GLenum type, GLvoid *row, GLvoid *column, GLvoid *span );
-typedef void (APIENTRYP PFNGLBLENDCOLORPROC) (GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha);
-typedef void (APIENTRYP PFNGLBLENDEQUATIONPROC) (GLenum mode);