[gn build] Set -fmsc-version=1920 on Windows
authorArthur Eubanks <aeubanks@google.com>
Thu, 3 Feb 2022 23:55:53 +0000 (15:55 -0800)
committerArthur Eubanks <aeubanks@google.com>
Thu, 3 Feb 2022 23:56:02 +0000 (15:56 -0800)
commitaaf2a47b1b08e6a06fd74e12746dff97a9d9e6fc
treed16c4fef16165a775fdf34c28b97646c2c7aee9b
parent55de669660cb1523cf83c98e8c0cb133ec279383
[gn build] Set -fmsc-version=1920 on Windows

Now that the minimum version version of MSVC required to build LLVM has
been bumped, we see

  ../../llvm/include\llvm/Support/Compiler.h(94,2): error: LLVM requires
  at least VS 2019.
  #error LLVM requires at least VS 2019.

e.g. http://45.33.8.238/win/53703/step_4.txt

1920 corresponds to the earliest version of VS 2019.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D118713
llvm/utils/gn/build/BUILD.gn