mozilla/rr — pull request #1344 by froydnj (2014-10-16 16:20:54+00:00)
Title: add support for getgroups, getres{u,g}id

x86-64 needs the `getgroups(2)` syscall to pass some tests. `getresuid(2)` and `getresgid(2)` need to be supported for parity with x86 (presumably for firefox?).

Also added a test to make sure we do the right thing with the 16-bit {u,g}id syscalls. Not enthused about the x86-64 case, but I'm not sure what we can do better there.