Windows: Merge user-provided manifests into compiled resource
Previously we merged user-provided manifests only into the manifest file given to the linker. Merge them into the manifest file that is compiled as a resource too.
Original Description
Most projects usually only define one manifest per library or executable. This commit will automatically embed the user provided manifest if the target only has a single manifest added.Fixes: #18710 (closed)
Topic-rename: win-user-manifest-rc