Casts from std::string -> cmStdString were high on the list of things
taking up time. Avoid such implicit casts across function calls by just
using std::string everywhere.
The comment that the symbol name is too long is no longer relevant since
modern debuggers alias the templates anyways and the size is a
non-issue since the underlying methods are generated since it's
inherited.
The coverage global should be in the local namespace. This means the global
will be ^ZZCOVERAGE instead of ^COVERAGE. Change the parser to look for ^ZZCOVERAGE
instead of the old ^COVERAGE