Simple but crucial bug fix to gdb

[Michael Snyder]

"Frank Ch. Eigler" wrote:
> 
> Daniel Berlin <dan@cgsoftware.com> writes:
> 
> : [...]
> : However, we should *never* see a case where pst is NULL, and
> : textlow_not_set is 1, at the point we see a function.
> : [...]
> 
> Would a gdb_assert() to this effect satisfy all sides?

gdb_assert causes an abort if the conditional fails.
I generally think it's better if the debugger doesn't abort
(unles it's believed to be in an unrecoverable state).