Fix gdbserver/MI testing regression
Commit 51f77c3704a6 ("Add testing infrastruture bits for running with
MI on a separate UI") broke MI testing with native-gdbserver:
$ make check RUNTESTFLAGS="--target_board=native-gdbserver mi-var-child.exp"
...
Running .../src/binutils-gdb/gdb/testsuite/gdb.mi/mi-var-child.exp ...
can't unset "inferior_spawn_id": no such variable
while executing
"unset inferior_spawn_id"
(procedure "close_gdbserver" line 20)
invoked from within
"close_gdbserver"
...
When testing with gdbserver, gdb_exit is overridden with a special
version that calls close_gdbserver, which clears inferior_spawn_id.
The problem is that the commit mentioned above made
gdb_exit/mi_gdb_exit clear inferior_spawn_id too, and clearing a
non-existing variable is a tcl error.
Since gdb_exit/mi_gdb_exit always clears inferior_spawn_id now, the
fix is simply to stop clearing it in close_gdbserver.
gdb/testsuite/
2016-06-30 Pedro Alves <palves@redhat.com>
* lib/gdbserver-support.exp (close_gdbserver, gdb_exit): Don't
unset inferior_spawn_id.2 files changed
