[lldb] [Host/{free,net}bsd] Fix process matching by name

Fix process matching by name to make 'process attach -n ...' work.

The process finding code has an optimization that defers getting
the process name and executable format after the numeric (PID, UID...)
parameters are tested.  However, the ProcessInstanceInfoMatch.Matches()
method has been matching process name against the incomplete process
information as well, and effectively no process ever matched.

In order to fix this, create a copy of ProcessInstanceInfoMatch, set
it to ignore process name and se this copy for the initial match.
The same fix applies to FreeBSD and NetBSD host code.

Differential Revision: https://reviews.llvm.org/D90454