[symbolizer] Support symbol+offset lookup (#75067)

GNU addr2line supports lookup by symbol name in addition to the existing
address lookup. llvm-symbolizer starting from
e144ae54 supports lookup by symbol name.
This change extends this lookup with possibility to specify optional
offset.

Now the address for which source information is searched for can be
specified with offset:

    llvm-symbolize --obj=abc.so "SYMBOL func_22+0x12"

It decreases the gap in features of llvm-symbolizer and GNU addr2line.
This lookup now is supported for code only.

Migrated from: https://reviews.llvm.org/D139859
Pull request: https://github.com/llvm/llvm-project/pull/75067