Fix build: Should use prebuilt version of clang instead of platform one.

Platform version of llvm needs to be upgraded regularly for platform bug
fixes and platform improvement in general. The new version of platform clang
doesn't handle gnu_inline attribute 100%. We should use prebuilt
toolchain for compiler for libpng.

We can turn back on LOCAL_CLANG after it is properly implemented, using

Currently, libpng.git is the only project that runs into gnu_inline problem.
We have to turn off wrong dependency on the platform clang only here.

Change-Id: I22429323e797ed6142e72f91a351ace3fdda3fc8
1 file changed