pgsql: psql: include intra-query "--" comments in what's sent to the se

psql: include intra-query "--" comments in what's sent to the server.

psql's lexer has historically deleted dash-dash (single-line) comments
from what's collected and sent to the server.  This is inconsistent
with what it does for slash-star comments, and people have complained
before that they wish such comments would be captured in the server log.
Undoing the decision completely seems like too big a behavioral change,
however.  In particular, comments on lines preceding the start of a
query are generally not thought of as being part of that query.

What we can do to improve the situation is to capture comments that
are clearly *within* a query, that is after the first non-whitespace,
non-comment token but before the query's ending semicolon or backslash
command.  This is a nearly trivial code change, and it affects only a
few regression test results.

(It is tempting to try to apply the same rule to slash-star comments.
But it's hard to see how to do that without getting strange history
behavior for comments that cross lines, especially if the user then
starts a new query on the same line as the star-slash.  In view of
the lack of complaints, let's leave that case alone.)

Discussion: https://postgr.es/m/CAJcOf-cAdMVr7azeYR7nWKsNp7qhORzc84rV6d7m7knG5Hrtsw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/83884682f4df96184549b91869a1cf79dafb4f94

Modified Files
--------------
contrib/pg_stat_statements/expected/pg_stat_statements.out | 2 +-
src/fe_utils/psqlscan.l                                    | 9 ++++-----
src/test/regress/expected/aggregates.out                   | 4 ++--
src/test/regress/expected/generated.out                    | 4 ++--
src/test/regress/expected/with.out                         | 4 ++--
5 files changed, 11 insertions(+), 12 deletions(-)