Fix build after recent regex tests addition (make it be an addition, and
don't forget tests/libtre)

Add a test for PR/58910

Adjust for conditional NLS

Replace MKMAN with NOMAN as suggested by christos@. Allows
userland to build when building man pages.

Sanitize the regex test cases.

- Merge h_regex_att (att.c) and t_regex_att.sh into a single C test program.
The former was really a test program, and the latter just a very strange
driver for it

Sanitize the regex test cases.

- Merge h_regex_att (att.c) and t_regex_att.sh into a single C test program.
The former was really a test program, and the latter just a very strange
driver for it.

- Stop using awk to generate the shell test programs. This is unnecessary
and confusing. Instead, change t_regex.sh to generate the test case
functions on the fly with eval (as done in many other places).

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make the standard tests optional.

skip the association that does not match with our implementation.

Add the AT&T regex tests

Arrange so that the same tests can be used by libtre.

Don't use 'nul' in filenames as windows will belch.
(Caught by importing the tree into mercurial)

- Use PROGS instead of PROG so that we can co-exist with TESTS_C
- Make the helper program compile again.

Add a test to check for DoS attacks against regcomp/regexec. From
Maksymilian Arciemowicz.

Ouch - forgot the include this earlier.