Show the gcc being used

Change-Id: Ic1eb943c7cc98742b831cc73072e98f1f2e099ff
Fixes for GCC 4.8 / 4.9 + linaro prefix support

The fixes for GCC 4.8 / 4.9 are from tonyp/android_build@f67b8334c3d696ed863da238448675546167984b

So it is possible to use a toolchain labeled: linaro-4.8

Change-Id: I528f5c5ef5bd889472d5cf2a5be2501d6fcc968d