MFC r269902,r270101:

r269902:

Convert bin/sh/tests to ATF

The new code uses a "test discovery mechanism" to determine
what tests are available for execution

The test shell can be specified via:

kyua test -v test_suites.FreeBSD.bin.sh.test_shell=/path/to/test/sh

Sponsored by: EMC / Isilon Storage Division
Approved by: jmmv (mentor)
Reviewed by: jilles (maintainer)

r270101 (by jilles):

sh: Don't hardcode relative paths in the tests stderr files.

These paths have had to be adjusted to changes in the testsuite runner
several times, so modify the tests to remove the need for such adjustment.

A cp in functional_test.sh is now unneeded, but this matters little in
performance.

MFC r287081: sh: Don't create bad parse result when postponing a bad
substitution error.

An invalid substitution like ${var@} does not cause a parse error but is
stored in the intermediate representation, to be written as part of the
error message. If there is a CTL* byte in the stored part, this confuses
some code such as the code to skip an unused alternative such as in
${var-alternative}.

To keep things simple, do not store CTL* bytes.

Found with afl-fuzz.

MFC r287081: sh: Don't create bad parse result when postponing a bad
substitution error.

An invalid substitution like ${var@} does not cause a parse error but is
stored in the intermediate representation, to be written as part of the
error message. If there is a CTL* byte in the stored part, this confuses
some code such as the code to skip an unused alternative such as in
${var-alternative}.

To keep things simple, do not store CTL* bytes.

Found with afl-fuzz.