[clang] [clang][analyzer] Added Abstract VAList region normalization into MemRegionManager (PR #181948)

[Donát Nagy via cfe-commits]

NagyDonat wrote:

@tahadostifam How did you work on this "for several days" without noticing that the tests are not passing?

Running the tests is a practically unavoidable step of development, even experienced developers use it to validate that their changes are correct.

https://github.com/llvm/llvm-project/pull/181948