pgsql: Tighten up Windows CRLF conversion in our TAP test scripts.

Tighten up Windows CRLF conversion in our TAP test scripts.

The previous approach was to search-and-destroy all \r occurrences
no matter what.  That seems more likely to hide bugs than anything
else; indeed it seems to be hiding one now.  Fix things so that
we only transform \r\n to \n.

Side effects: must do this before, not after, chomp'ing if we're
going to chomp, else we'd fail to clean up a trailing \r\n.  Also,
remove safe_psql's redundant repetition of what psql already did;
else it might reduce \r\r\n to \n, which is exactly the scenario
I'm hoping to expose.

Perhaps this should be back-patched, but for now I'm content to
see what happens in HEAD.

Discussion: https://postgr.es/m/412ae8da-76bb-640f-039a-f3513499e53d@gmx.net

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/91bdf499b37b0bbef34e2bab5cc40dde52bda52c

Modified Files
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src/bin/pg_rewind/t/RewindTest.pm |  2 +-
src/test/perl/PostgresNode.pm     | 13 ++++++-------
src/test/perl/TestLib.pm          |  2 +-
3 files changed, 8 insertions(+), 9 deletions(-)