MOZ_DEBUG_DEFINES are essentially defines used everywhere. So treat them as
feeding the initial value for DEFINES in each moz.build sandbox. This allows
the kind overrides that was done in the past by resetting MOZ_DEBUG_DEFINES
in Makefiles.
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