Avoid redefinition of __STDC_CONSTANT_MACROS.

(cherry picked from 5c97ecc017eb90037ab8a2cf8ff7066982bb2c50)

Change-Id: I5cf69b6197f8d1ff0f0f4bfa589c82b36d1513f4
Merge "Avoid redefinition of __STDC_CONSTANT_MACROS."
Make LLVM build on AArch64.

bug 13343378

Change-Id: I4152d2437a144645fa0b5a425b7bfdcb3a2a5594
Merge "Make LLVM build on AArch64."
Enable x86_64 build

Change-Id: I9feecd151ab91351c42e230df4eb3aa3af76799a
Merge "Enable x86_64 build"