Misc fixes in package-release, run-tests-all, and add a test

1. In package-release.sh after unpacking GCC, remove ld.mcld
   which may deployed/packaged earlier
2. Fix to run test on mips-r2 devices
3. Add a simple test "stat"

Change-Id: I9d71692c42d98bf473420fb460d259532dc4237c
5 files changed