package/bullet: extras needs dlfcn.h and threads

extras needs dynamic library (dlfcn.h) and threads

Fixes:
 - http://autobuild.buildroot.org/results/a2609de74c08d9287beb839b93794161a7868e30
 - http://autobuild.buildroot.org/results/3e961d40f3d7003061eee0f7dc476d26c444bd7b

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/bullet/bullet.mk

@@ -16,4 +16,11 @@ BULLET_CONF_OPTS = -DBUILD_UNIT_TESTS=OFF \
 	-DBUILD_BULLET2_DEMOS=OFF \
 	-DBUILD_BULLET3=OFF
 
+# extras needs dlfcn.h and threads
+ifeq ($(BR2_STATIC_LIBS):$(BR2_TOOLCHAIN_HAS_THREADS),:y)
+BULLET_CONF_OPTS += -DBUILD_EXTRAS=ON
+else
+BULLET_CONF_OPTS += -DBUILD_EXTRAS=OFF
+endif
+
 $(eval $(cmake-package))