COMMON_INTERCEPTOR_COPY_STRING only had an implementation in msan, but it would make sense to implement it for asan as well.
This was added due to false negative in ASan on buggy strlcpy usage. Added a regression test for strlcpy as well.
rdar://83965778
Note that the passed size argument is the size of the destination buffer. src can be an arbitrarily long string. I think we should model the touched ranges a bit more precisely.