Added a new test case to test signals with.

Added frame relative frame selection to "frame select". You can now select
frames relative to the current frame (which defaults to zero if the current
frame hasn't yet been set for a thread):

The gdb "up" command can be done as:
(lldb) frame select -r 1
The gdb "down" command can be done as:
(lldb) frame select -r -1

Place the following in your ~/.lldbinit file for "up" and "down":

command alias up frame select -r 1
command alias down frame select -r -1

llvm-svn: 116176