swift linker flags are propagated improperly for mixed language projects on Windows
Trying to port libdispatch to the new Swift support, I noticed that the following causes problems on Windows:
cmake_minimum_required(VERSION 3.14.20190523) project(P LANGUAGES C CXX Swift)
The C/C++ checks for the linker add
/MACHINE:x64 to the linker flags which propagate to the Swift check and cause issues.