cmake: Add compiler source tests.
Implement the 3 header checks currently run by configure: - aom/aom_integer.h - pthread.h - unistd.h Note: the aom_integer.h check is only present to maintain parity with the behavior of the original build system. The output variable it sets is not actually used in the aom sources. BUG=https://bugs.chromium.org/p/aomedia/issues/detail?id=76 Change-Id: I53479a1253a977d6fdb7b0d6e5233686d79315e3
Showing with 125 additions and 0 deletions