[ELF] - Fix for: PR29093 - version script does not support [chars] wildcards

GNU ld supports [chars] wildcards in version scripts, to match a single instance of any of the chars.
Here is an extern example from libstdc++'s version script in FreeBSD:

extern "C++"
{
...

std::locale::_[T-Za-z]*;                                                                                                       
std::[A-Zm]*;                                                            
std::n[^u]*;                                                             
std::nu[^m]*;                                                            
std::num[^e]*;
...

}

Patch adds support for scripts above. This is PR29093.

Differential revision: https://reviews.llvm.org/D23803

llvm-svn: 280799