Option to disable frame checking

[Joshua Watt]

I'm using GDB on a ARM architecture with a custom OS
(--target=arm-eabi). In certain cases, we call functions on a
completely separate stack from the one that the thread normally uses.
In these cases, GDB fails to do a backtrace through the function call
with an UNWIND_INNER_ID error, even though all the correct stack
unwinding debug information is present. Is it acceptable to make a
patch that allows this check to be turned off (i.e. "set
frame-inner-check off" or similar), or is there another method that is
more acceptable?

-- 
Joshua Watt