The patch removes 455 occurrences of FAIL_ON_WARNINGS from moz.build files, and
adds 78 instances of ALLOW_COMPILER_WARNINGS. About half of those 78 are in
code we control and which should be removable with a little effort.
--HG--
extra : rebase_source : 82e3387abfbd5f1471e953961d301d3d97ed2973
There is very little benefit to having another layer of moz.build files, and
removing them will speed up the build a minimal amount. It also paves the way
for removing TEST_DIRS, which could simplify the build system somewhat.