st/egl: Fix build on FreeBSD.

There is no libdl on FreeBSD.  Based on patch from Thinker
<thinker@branda.to>, which is against 7.8.

This fixes fdo bug #29093.
(cherry picked from commit 08f4bc07e4)

configs/autoconf.in

@@ -29,6 +29,9 @@ X11_CFLAGS = @X11_CFLAGS@
 GLW_CFLAGS = @GLW_CFLAGS@
 GLUT_CFLAGS = @GLUT_CFLAGS@
 
+# dlopen
+DLOPEN_LIBS = @DLOPEN_LIBS@
+
 # Assembler
 MESA_ASM_SOURCES = @MESA_ASM_SOURCES@
 GLAPI_ASM_SOURCES = @GLAPI_ASM_SOURCES@

configs/default

@@ -121,6 +121,8 @@ APP_LIB_DEPS    = $(EXTRA_LIB_PATH) -L$(TOP)/$(LIB_DIR) -l$(GLUT_LIB) -l$(GLU_LI
 APP_LIB_DEPS = -lm
 X11_LIBS = -lX11
 
+DLOPEN_LIBS = -ldl
+
 # Installation directories (for make install)
 INSTALL_DIR = /usr/local
 INSTALL_LIB_DIR = $(INSTALL_DIR)/$(LIB_DIR)

configure.ac

@@ -398,6 +398,7 @@ dnl Check to see if dlopen is in default libraries (like Solaris, which
 dnl has it in libc), or if libdl is needed to get it.
 AC_CHECK_FUNC([dlopen], [],
     [AC_CHECK_LIB([dl], [dlopen], [DLOPEN_LIBS="-ldl"])])
+AC_SUBST([DLOPEN_LIBS])
 
 dnl See if posix_memalign is available
 AC_CHECK_FUNC([posix_memalign], [DEFINES="$DEFINES -DHAVE_POSIX_MEMALIGN"])

src/gallium/winsys/drm/Makefile.egl

@@ -11,7 +11,7 @@
 
 EGL_DRIVER_OBJECTS = $(EGL_DRIVER_SOURCES:.c=.o)
 
-common_LIBS = -ldrm -lm -ldl
+common_LIBS = -ldrm -lm $(DLOPEN_LIBS)
 
 x11_ST = $(TOP)/src/gallium/state_trackers/egl/libeglx11.a
 x11_LIBS = $(common_LIBS) -lX11 -lXext -lXfixes