[compiler-rt] [ubsan-minimal] Switch to weak symbols for callbacks to allow overriding in client code (PR #119242)

[Kirill Stoimenov via llvm-commits]

kstoimenov wrote:

I renamed report_this_error to __sanitizer_report_ubsan_error so we have a single handler now. PTAL. 

https://github.com/llvm/llvm-project/pull/119242