[clang] [clang][analyzer] Clear `ObjCMethodCall`'s cache between runs (PR #161327)

[Donát Nagy via cfe-commits]

https://github.com/NagyDonat approved this pull request.

LGTM, with the disclaimer that I'm unfamiliar with the handling of Objective-C in the analyzer.

Obviously this approach with the global cache is not exactly "best practices", but the PR suggests a straightforward fix for a concrete issue, so there is no reason to oppose it.

https://github.com/llvm/llvm-project/pull/161327