[lldb-dev] process.gdb-remote crashes Part 3

[arvid.picciani at nokia.com]

In source/API/SBFrame.cpp, it is assumed that GetRegisterContext() is not null, and there is no way in the public API to check it either.
With the gdb plugin, sometimes the Frame is valid, but the register context is not, leading to a crash on GetSP for example.
There should probably either be a way to check the validity from the outside, or SBFrame::IsValid should only return true if GetRegisterContext works 
(the frame is unusable anyway, if it doesn't)