<rdar://problem/13384801>

Make lldb_private::RegularExpression thread safe everywhere. This was done by removing the m_matches array from the lldb_private::RegularExpression class and putting it into the new lldb_private::RegularExpression::Match class. When executing a regular expression you now have the option to create a lldb_private::RegularExpression::Match object and pass a pointer in if you want to get parenthesized matching. If you don't want any matching, you pass in NULL. The lldb_private::RegularExpression::Match object is initialized with the number of matches you desire. Any matching strings are now extracted from the lldb_private::RegularExpression::Match objects. This makes the regular expression objects thread safe and as a result many more regex objects were turned into static objects that end up using a local lldb_private::RegularExpression::Match object when executing.