-fms-compatibility-version was defaulting to 18 (VS 2013), which is a pain if your environment is pointing to version 19 (VS 2015) libraries.
If cl.exe can be found, this patch uses its version number as the default instead. It re-uses the existing code to find the Visual Studio binaries folder and WinAPI methods to check its version. You can still explicitly specify a compatibility version on the command line. If you don't have cl.exe, this should be a no-op and you'll get the old default of 18.
This affected the tests, which assumed that if you didn't specific a version, that it would default to 18, but this won't be true for all machines. So a couple test cases had to be eliminated and a couple others had to be tweaked to allow for various outputs.
Addresses: https://llvm.org/bugs/show_bug.cgi?id=27215
Differential Revision: http://reviews.llvm.org/D20136
llvm-svn: 269515
The object file format is sometimes overridden for MSVC targets to use
ELF instead of COFF. Make sure we preserve this choice when setting the
msvc version number in the triple.
llvm-svn: 239388
Encoding the version into the triple will allow us to communicate to
LLVM what functions it can expect to depend upon in the implementation.
llvm-svn: 239273
Adrian McCarthy