cm: Use fork of aarch64 gcc for darwin as well

* 5515fd9b47 introduced a fork of the gcc with the A53 errata workarounds,
    but the darwin-x86 aarch64 gcc needs them as well.

Change-Id: Ia7302be4885423d52268066c7ffded9d15ff812a
Signed-off-by: Brandon McAnsh <brandon.mcansh@gmail.com>

default.xml

@@ -536,7 +536,7 @@
   <project path="prebuilts/devtools" name="platform/prebuilts/devtools" remote="aosp" />
   <project path="prebuilts/eclipse" name="platform/prebuilts/eclipse" remote="aosp" />
   <project path="prebuilts/gcc/darwin-x86/aarch64/aarch64-linux-android-4.8" name="platform/prebuilts/gcc/darwin-x86/aarch64/aarch64-linux-android-4.8" groups="pdk,darwin,arm" remote="aosp" />
-  <project path="prebuilts/gcc/darwin-x86/aarch64/aarch64-linux-android-4.9" name="platform/prebuilts/gcc/darwin-x86/aarch64/aarch64-linux-android-4.9" groups="pdk,darwin,arm" remote="aosp" />
+  <project path="prebuilts/gcc/darwin-x86/aarch64/aarch64-linux-android-4.9" name="CyanogenMod/android_prebuilts_gcc_darwin-x86_aarch64_aarch64-linux-android-4.9" groups="pdk,darwin,arm" />
   <project path="prebuilts/gcc/darwin-x86/arm/arm-eabi-4.8" name="platform/prebuilts/gcc/darwin-x86/arm/arm-eabi-4.8" groups="pdk,darwin,arm" remote="aosp" />
   <project path="prebuilts/gcc/darwin-x86/arm/arm-linux-androideabi-4.8" name="platform/prebuilts/gcc/darwin-x86/arm/arm-linux-androideabi-4.8" groups="pdk,darwin,arm" remote="aosp" />
   <project path="prebuilts/gcc/darwin-x86/host/headers" name="platform/prebuilts/gcc/darwin-x86/host/headers" groups="pdk,darwin" remote="aosp" />