build: substitute X11_INCLUDES variable

There are a few automake files that reference $(X11_INCLUDES) such as
src/glx/Makefile.am but configure.ac wasn't declaring the variable for
substitution. This would break builds of glx if libxcb, for example, was
installed in its own prefix since AM_CFLAGS wouldn't coincidentally
list the needed include path in that case.

Reviewed-by: Matt Turner <mattst88@gmail.com>

diff --git a/configure.ac b/configure.ac
index cb65467..b83078f 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -905,6 +905,7 @@ GLESv1_CM_PC_LIB_PRIV="-lm -lpthread $DLOPEN_LIBS"
 GLESv2_LIB_DEPS="$LIBDRM_LIBS -lm -lpthread $DLOPEN_LIBS"
 GLESv2_PC_LIB_PRIV="-lm -lpthread $DLOPEN_LIBS"
 
+AC_SUBST([X11_INCLUDES])
 AC_SUBST([GL_LIB_DEPS])
 AC_SUBST([GL_PC_REQ_PRIV])
 AC_SUBST([GL_PC_LIB_PRIV])