Be less picky about EACCES in file test predicates

Problem reported by Tino Calancha (Bug#37445) and others.
* src/fileio.c (PICKY_EACCES): New constant, false by default.
(file_test_errno): Ignore EACCES if not picky.
(check_file_access): Investigate EACCES problems further
if picky.
1 job for master in 56 minutes and 30 seconds (queued for 1 second)
Status Job ID Name Coverage
failed #3340


Name Stage Failure
test-all Test
Makefile:319: recipe for target 'check-doit' failed
make[2]: *** [check-doit] Error 1
make[2]: Leaving directory '/builds/emacs/emacs/test'
Makefile:294: recipe for target 'check-expensive' failed
make[1]: *** [check-expensive] Error 2
make[1]: Leaving directory '/builds/emacs/emacs/test'
Makefile:959: recipe for target 'check-expensive' failed
make: *** [check-expensive] Error 2
ERROR: Job failed: exit code 1