RFC: Please suggest the build & test config combinations for CI

[lazyparser]

Hi all,

I have built a CI service for riscv-gnu-toolchain, with a few configs added.

https://ci.rvperf.org/view/GNU/

Currently the coverage of build & regression testing is not sufficient. I realized that there are too many of branch/configure/platform/hostOS combinations, so that it is no possible to just run all the combinations.

Build config includes:

• OS type and version
• host toolchain: type and version
• branch of riscv-gnu-toolchain
• branches/commits of submodules (if you changed manually)
• configure command
• make commands
• other things need to care about for reproducing the result

Feel free to drop your build configs in comments!
Please help. I really appreciate it :)

[lazyparser]

• master branch. full regression tests. ubuntu1804
  https://ci.rvperf.org/job/riscv-gnu-toolchain-master-detailed-regresstion-ubuntu1804/

• master branch. full regression tests. ubuntu2004. bump QEMU to v5.2.0
  https://ci.rvperf.org/job/riscv-gnu-toolchain-master-detailed-regresstion-2004/

• sync-after-git-clone branch. ubuntu1804
  https://ci.rvperf.org/job/riscv-gnu-toolchain-sync-after-git-clone-ubuntu1804/

• rvv-intrinsic branch. ubuntu1804
  https://ci.rvperf.org/job/riscv-gnu-toolchain-rvv-intrinsic-ubuntu1804/

[lazyparser]

#851 and #852 provide enough information