Code review comment for lp://staging/~berolinux/linaro-android-build-tools/support-dual-toolchain-tarballs

The naming is fine. This prefix is the triplet so 'TOOLCHAIN_TRIPLET' might be better. Many tools like the kernel use CROSS_COMPILE instead.

See:
 http://www.gnu.org/s/hello/manual/autoconf/Specifying-Target-Triplets.html#Specifying%20Names

We omit the vendor if it is 'none' so instead of the more common/canonical arm-none-linux-gnueabi we use arm-linux-gnueabi. Same for arm-none-eabi where 'none' means no OS.