Pacify GCC 9.1

* src/intervals.c (set_intervals_multibyte_1): Omit unused temps.
* src/xdisp.c (display_mode_element): Use !NILP instead of
STRINGP.  This convinces GCC we’re not dereferencing a
possibly-null pointer, and should be a bit faster anyway.
1 job for master in 52 minutes and 34 seconds (queued for 1 second)
Status Job ID Name Coverage
failed #1694


Name Stage Failure
test-all Test
Makefile:318: recipe for target 'check-doit' failed
make[2]: *** [check-doit] Error 1
make[2]: Leaving directory '/builds/emacs/emacs/test'
Makefile:293: recipe for target 'check-expensive' failed
make[1]: *** [check-expensive] Error 2
make[1]: Leaving directory '/builds/emacs/emacs/test'
Makefile:957: recipe for target 'check-expensive' failed
make: *** [check-expensive] Error 2
ERROR: Job failed: exit code 1