[lldb-dev] Release_38 cherry-picks

[Francis Ricci via lldb-dev]

Hi all,

I'd like to merge a few more small bugfixes onto the 38 release
branch. I'll plan to do it tomorrow (3/7) in the evening if I don't
hear any objections. Thanks!

r259433 - Fix getCompiler in unit testing framework on compiler symlinks
r267459 - Add missing qRegisterInfo option to gdbremote testcase
r271899 - Don't remove PIE executables when using svr4 packets

Francis