PPC: Force PPC linux to use gcc and gcc 4.8.3 changes for AIX
PPC: Force PPC linux to use gcc and gcc 4.8.3 changes for AIX

- We don't have clang for PPC, force use of gcc.
- Changes needed to compile/build on AIX with gcc 4.8.3 missed
from last review

	modified:   build/standalone.gypi

R=danno@chromium.org, svenpanne@chromium.org

BUG=

Review URL: https://codereview.chromium.org/1018543003

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#27254}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh