This commit switches Windows builds from Visual Studio 2013
to Visual Studio 2015 Update 1.
Previously, Visual Studio was installed on the builders as part
of the base system image. Starting with this commit, we obtain
Visual Studio from a pre-generated, self-contained archive
containing the executables, Windows SDK, and other support
files. This means that new Windows toolchains can be installed
without having to modify configuration of machines in automation!
The mozconfigs for Visual Studio 2015 are a bit different from
existing mozconfigs.
Because it appears to be completely redundant and not necessary,
the LIBPATH variable has been dropped.
The order of paths in PATH, LIB, and INCLUDE has changed. The new
order more accurately reflects what would be defined by
vcvarsall.bat.
As part of switching to Visual Studio 2015, the Universal CRT is
now required. So, the 2015 mozconfigs export WIN_UCRT_REDIST_DIR
to define the location to those files.
The switch to Visual Studio 2015 also involves the switch from
the Windows 8.1 SDK to the Windows 10 SDK. However, we still
target an old version of Windows, so this hopefully shouldn't
have any significant fallout.
It's worth noting that switching to Visual Studio 2015 makes
builds - especially PGO builds - significantly faster. Our
PGO build times in automation are ~1 hour faster. Our regular
builds appear to be a few minutes faster.
MozReview-Commit-ID: Pa5GW8V87Q
--HG--
extra : rebase_source : bff4fad17f781d8d21bdb941bdd500955d1e9f08
extra : amend_source : faa3038c290fdf5cdd3e24a45ba2a37490f68c17
extra : source : 56b27306d3257445f70374aa78fc5bd42ef300ce
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