Add initial NetBSD support in lldbsuite/test/lldbtest.py

[krytarowski]

Summary

Add new functions:

• expectedFailureNetBSD()
• expectedFlakeyNetBSD()
• skipIfNetBSD()

Add new NetBSD entry in:

• getPlatform()
• getHostPlatform()

Assume that libc++ is installed and use the GNU toolchain

[emaste]

packages/Python/lldbsuite/test/lldbtest.py

832–834

perhaps put after FlakeyLinux so we only have to move FreeBSD to put it in alpha order

2290–2291

This seems wrong; if a test needs libc++ it should either be skipped on NetBSD right now or use libc++

[joerg]

Two small cleanups, otherwise LGTM.

packages/Python/lldbsuite/test/lldbtest.py

1328

I'd prefer getPlatform() in ("linux", "freebsd", "netbsd") as more shorter.

2288

Same, self.getPlatform in ...

[krytarowski]

Thank you!