Minor update to build instructions: workaround a bug in cmake+make build files



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@178569 91177308-0d34-0410-b5e6-96231b3b80d8
Added "rb" and "rbr" aliases to fix regressions
when we changed "rb" to "rbreak".

<rdar://problem/13552724>


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@178573 91177308-0d34-0410-b5e6-96231b3b80d8
<rdar://problem/13516463>

Don't crash when there is no register context for a thread with kernel debugging. The kernel debugging uses the OperatingSystemPlugin that may behave badly when trying to get thread state, so be prepared to have invalid register contexts in threads.



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@178574 91177308-0d34-0410-b5e6-96231b3b80d8