monitor mode: deconflict with private global mangling

monitor mode: deconflict with private global mangling

The synthesized probe body for monitor mode control needs to refer to
globals that may be declared private inside a tapset, in order to
clear them.  It needs to pierce the mangling-based name-hiding, so
that when the synthetic fragment is symbol-resolved, it will find the
mangled private globals to manipulate.  This is implemented by an
optional mode-flag in the symresolution_info class to suppress
global-mangling.

The test script was:

   stap --monitor -p4 -e 'probe nd_syscall.* {}' -v