Revision 418964

A few more recent patches that were merged to upstream GDB:

- Handle version 1a of NT_PRPSINFO notes which include the pr_pid field.
- Replace patch-sigev with upstream version.  Note that upstream GDB
  doesn't define SIGLIBRT on older OS versions, so do that in the port
  Makefile instead.
- Use PT_GET_EVENT_MASK/PT_SET_EVENT_MASK (new in 12).
- Fix a bug where fork and LWP events weren't enabled in new child
  processes when following child processes after a fork.
- Handle "real" vfork done events via PTRACE_VFORK (new in 12).

PR:		211254
Approved by:	luca.pizzamiglio@gmail.com (maintainer)