Merge change 1642 into donut

* changes:
  Allow the build system to build Objective-C sources.
tree: 8343e6477aae02653c11b194cf05163264fc056b
  1. core/
  2. libs/
  3. target/
  4. tools/
  5. buildspec.mk.default
  6. cleanspec.mk
  7. envsetup.sh