glx: move __glXMesaProvider from GLcore module to glx module.

This treats the GLcore provider similar to DRI provider, using a subset of
XMesa as the GLcore interface.

GL/glx/Makefile.am

@@ -46,12 +46,13 @@ libglx_la_SOURCES = \
         glxdrawable.h \
         glxext.c \
         glxext.h \
-	glxvisuals.c \
+        glxglcore.c \
         glxscreens.c \
         glxscreens.h \
         glxserver.h \
         glxutil.c \
         glxutil.h \
+        glxvisuals.c \
         indirect_dispatch.c \
         indirect_dispatch.h \
         indirect_dispatch_swap.c \

GL/mesa/X/Makefile.am

@@ -22,8 +22,6 @@ AM_CFLAGS = \
 	-DXFree86Server \
 	@GLX_DEFINES@
 
-libX_la_SOURCES = xf86glx.c
-
 nodist_libX_la_SOURCES = \
                   xm_api.c \
 		  xm_buffer.c \