xlib: Remove macro guard with GLX_INDIRECT_RENDERING in xlib.c

According meson about with_glx == 'xlib' check only defied '-DUSE_XSHM',
so the macro check GLX_INDIRECT_RENDERING make no-sense, removed it.

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19221>

src/gallium/targets/libgl-xlib/xlib.c

@@ -105,29 +105,3 @@ extern void (*linker_foo(const unsigned char *procName))()
 {
    return glXGetProcAddress(procName);
 }
-
-
-/**
- * When GLX_INDIRECT_RENDERING is defined, some symbols are missing in
- * libglapi.a.  We need to define them here.
- */
-#ifdef GLX_INDIRECT_RENDERING
-
-#define GL_GLEXT_PROTOTYPES
-#include "main/glheader.h"
-#include "glapi/glapi.h"
-#include "glapi/glapitable.h"
-
-#define NAME(func)  gl##func
-
-#define DISPATCH(FUNC, ARGS, MESSAGE)		\
-   GET_DISPATCH()->FUNC ARGS
-
-#define RETURN_DISPATCH(FUNC, ARGS, MESSAGE) 	\
-   return GET_DISPATCH()->FUNC ARGS
-
-/* skip normal ones */
-#define _GLAPI_SKIP_NORMAL_ENTRY_POINTS
-#include "glapitemp.h"
-
-#endif /* GLX_INDIRECT_RENDERING */