(no bug) - explicitly unsupport --enable-static for xulrunner (like we did with Firefox). r=bsmedberg

xulrunner/confvars.sh

@@ -41,6 +41,7 @@ MOZ_APP_DISPLAYNAME=XULRunner
 MOZ_UPDATER=1
 MOZ_XULRUNNER=1
 MOZ_ENABLE_LIBXUL=1
+MOZ_STATIC_BUILD_UNSUPPORTED=1
 MOZ_APP_VERSION=$MOZILLA_VERSION
 MOZ_JAVAXPCOM=1
 if test "$MOZ_STORAGE"; then