Revert change to ExtUtils-Constant/t/Constant.t

Revert change to ExtUtils-Constant/t/Constant.t

Revert change to ExtUtils-Constant/t/Constant.t

prevent a spurious error output from test.pl when killing a cygwin pr…

…ocess

Under Cygwin a process can sometimes take a little while to spool down
after being killed. There already is code to wait a second and retry.
However if the process has already disappeared in the wait second, then the
retry is engaged anyhow and will then complain it can't find the process.

This change makes it so test.pl only truly attempts to kill a cygwin
process if it actually is still around.

This resolves the secondary bug in #18129.

(cherry picked from commit 57b919f26b5911913c97a93dd5238f7c8c2a6e5f)
Signed-off-by: Nicolas R <nicolas@atoomic.org>

Committer: Add contributor to AUTHORS

Windows needs access to path to find DLL files. so you can't clear it…

… for some taint tests

cpan/ExtUtils-Install: sync in CPAN version 2.16

Then bring all files into compliance with strict-by-default.

The version of EU-I we previously had, 2.14, suffered from a race
condition.  Patches were submitted to PTG for this problem but not
released to CPAN (2.16) until it was too late to get them into
perl-5.32.0.  Hence, they were not part of Perl 7 at our initial branch
point, alpha-00.  In the last two days we got smoke-test failures due to
the race condition.  So to avoid misleading smoke test failure reports,
let's pull in 2.16 and make it strict-compliant.

Signed-off-by: James E Keenan <jkeenan@cpan.org>

Fix leak GH #18054

This was a simple matter of one path failing to free the memory.

(cherry picked from commit 6841cd5977c2d35ad75233734c66983a65613fce)
Signed-off-by: Nicolas R <nicolas@atoomic.org>

Merge pull request #255 from jkeenan/repair-hints-files-20200830

hints files:  Relax strict vars

Merge pull request #189 from atoomic/alpha-dev-01a-v5-6-7

Restore 'use 5.x' behavior as it behaves in Perl 5

t/run/switches.t: TODO two failing tests