Initializer lists are only properly supported in 2015 and above.
Previous Visual Studio releases said they supported initializer lists
but silently produced bad code.
In generators such as Ninja that can run multiple "cl" processes that
refer to the same compiler .pdb file (/Fd) at the same time, MSVC from
Visual Studio 2013 complains:
fatal error C1041: cannot open program database '.../vc120.pdb';
if multiple CL.EXE write to the same .PDB file, please use /FS
According to "cl /?":
/FS force to use MSPDBSRV.EXE
Add the flag to compilation lines for this compiler version just after the
/Fd option.
Remove the old-style "Windows-cl.cmake" and its helper "cl.cmake". Load
the information through new-style "Platform/Windows-MSVC-<lang>.cmake"
files. Factor information common to C and CXX into a helper file
"Platform/Windows-MSVC.cmake" loaded from the per-language files.
Robert Maynard
Brad King