Move ports/geckolib/target to target/geckolib

.gitignore

@@ -6,7 +6,6 @@
 /ports/android/libs
 /ports/android/local.properties
 /ports/android/obj
-/ports/geckolib/target
 /python/_virtualenv
 /python/tidy/servo_tidy.egg-info
 *~

python/servo/build_commands.py

@@ -332,7 +332,7 @@ def build_geckolib(self, jobs=None, verbose=False, release=False):
             opts += ["--release"]
 
         env = self.build_env()
-        env["CARGO_TARGET_DIR"] = path.join(self.context.topdir, "ports/geckolib/target")
+        env["CARGO_TARGET_DIR"] = path.join(self.context.topdir, "target", "geckolib")
 
         build_start = time()
         with cd(path.join("ports", "geckolib")):