Even though we compile C code as C99, we used to need
-Wdeclaration-after-statement because MSVC didn't allow declarations after
statements.
However, Visual Studio 2013 added support, so we can now merrily mix
declarations and statements everywhere. Hooray.
--HG--
extra : rebase_source : 00a89fed733008785429827408a0c6c466971080
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
