Combine few relatively small changes into one:
- implement internal_ptrace() and internal_clone() for NetBSD
- add support for stoptheworld based on the ptrace(2) API
- define COMPILER_RT_HAS_LSAN for NetBSD
- enable tests for NetBSD/amd64
Inspired by the original implementation by Christos Zoulas in netbsd/src for GCC.
The implementation is in theory CPU independent through well defined macros
across all NetBSD ports, however only the x86_64 version was tested.
Looks like you completely forked sanitizer_stoptheworld_netbsd_libcdep
in this case you don't new internal_
up to you if you like to keep them