pgsql: Add configure probe for rl_completion_suppress_quote.

Add configure probe for rl_completion_suppress_quote.

I had supposed that all versions of Readline that have filename
quoting hooks also have the rl_completion_suppress_quote variable.
But it seems OpenBSD managed to find a version someplace that does
not, so we'll have to expend a separate configure probe for that.

(Light testing suggests that this version also lacks the bugs that
make it necessary to frob that variable. Hooray!)

Per buildfarm.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/c32704441d47cc1cbb36367a429814511edb6ffd

Modified Files
--------------
config/programs.m4 | 20 +++++++++++++++++++-
configure | 39 +++++++++++++++++++++++++++++++++++++++
src/bin/psql/tab-complete.c | 7 ++++---
src/include/pg_config.h.in | 4 ++++
src/tools/msvc/Solution.pm | 1 +
5 files changed, 67 insertions(+), 4 deletions(-)