tree fbcb0b8234099dcfa2f16c92705bd22d54e074bc
parent d421274e3e11a0e6480358faa8a8e5cf48d7b3c2
author Brad King <brad.king@kitware.com> 1595514659 -0400
committer Brad King <brad.king@kitware.com> 1595516075 -0400

VS: Restore toleration of target-wide -TP flag with MSVC

Since commit 3b547e2e4b (VS: Simplify logic adding source file C/C++
language flag to MSVC, 2020-05-15, v3.18.0-rc1~139^2~1) we only add a
per-source language selection flag when the source file extension does
not match the compiler's default.  This approach breaks when a project
adds a target-wide `-TP` flag.

Although such projects likely did not work with non-VS generators, we
did support them before in Visual Studio generators.  Add a special case
to tolerate such flags again.

Fixes: #21005