Description
I noticed that since #126315 the libc premerge testing matrix for generating configurations is only testing Build|Debug|MinSizeRel for one OS instead of the full list of OS options. I made a patch to fix this but also wanted to discuss what configurations we actually want in the libc premerge vs the general premerge testing in .github/workflows/premerge.yaml vs the post commit buildbots.
Do people have opinions on whether we need to build all three of the options Debug/Release/MinSizeRel in premerge (how often would there be a build failure that appears in one but not the other)? IIUC MinSizeRel was only used to save space in the github actions workers, but if we build all three then that doesn't make as much sense.
The main premerge also builds libc (only on linux, release mode, overlay mode). Don't know how we should manage the overlap (only build libc in the libc-specific script? maybe depends on how much capacity it uses?)
Also, if we do keep all the OS's and build configs in the libc premerge pipeline, maybe we can consider removing some of the overlapping post commit workers.