ws/i965: add butt-ugly linker hack

Need more linker magic to keep the glX symbols externally visible even
though they started off in a .a file.

src/gallium/winsys/drm/i965/xlib/xlib_i965.c

@@ -360,3 +360,18 @@ struct xm_driver xlib_i965_driver =
 };
 
 
+
+
+
+/***********************************************************************
+ *
+ * Butt-ugly hack to convince the linker not to throw away public GL
+ * symbols (they are all referenced from getprocaddress, I guess).
+ */
+extern void (*linker_foo(const unsigned char *procName))();
+extern void (*glXGetProcAddress(const unsigned char *procName))();
+
+extern void (*linker_foo(const unsigned char *procName))()
+{
+   return glXGetProcAddress(procName);
+}