cmCxxModuleMapper: add a query for the open mode for the modmap

GCC (MinGW) wants to use \n on Windows too.

Fixes: #25974 (closed)

---

Backport: release
Manual-backport: release-3.28

changed milestone to %3.29.4

added area:cxxmodules comp:gcc os:windows workflow:wip labels

requested review from @brad.king

added comp:mingw label

added 1 commit

• 9e2f31ec - cmCxxModuleMapper: add a query for the open mode for the modmap

Compare with previous version

Warnings:

• Eligible for the 3.28.x branch.
• Eligible for the 3.29.x branch.

The warnings do not need to be fixed, but it is recommended to do so.

added workflow:in-review label and removed workflow:wip label

Do: stage

added workflow:nightly-testing label and removed workflow:in-review label

Do: merge

mentioned in commit ea44e63a

mentioned in commit 76fa2e8f

merged manually

removed workflow:nightly-testing label

mentioned in commit 32a8d5a4

changed milestone to %3.28.6