pgsql: Fix boilerplate comments in btree_gist

Fix boilerplate comments in btree_gist

A few of these were copy-pasted wrong, like the comment "Bytea ops" in
btree_numeric.c. Instead of fixing the incorrect ones, replace them
all with generic comment "GiST support functions".

Also tidy up the inconsistent newlines between various functions while
we're at it.

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/9370978da8ac8f0e31867859282b0f2be724fe48

Modified Files
--------------
contrib/btree_gist/btree_bit.c | 11 ++---------
contrib/btree_gist/btree_bool.c | 9 ++-------
contrib/btree_gist/btree_bytea.c | 15 ++-------------
contrib/btree_gist/btree_cash.c | 11 +++--------
contrib/btree_gist/btree_date.c | 12 ++----------
contrib/btree_gist/btree_enum.c | 8 ++------
contrib/btree_gist/btree_float4.c | 10 ++--------
contrib/btree_gist/btree_float8.c | 11 +++--------
contrib/btree_gist/btree_inet.c | 10 ++--------
contrib/btree_gist/btree_int2.c | 11 +++--------
contrib/btree_gist/btree_int4.c | 11 ++---------
contrib/btree_gist/btree_int8.c | 10 ++--------
contrib/btree_gist/btree_interval.c | 8 ++------
contrib/btree_gist/btree_macaddr.c | 10 ++--------
contrib/btree_gist/btree_macaddr8.c | 13 ++-----------
contrib/btree_gist/btree_numeric.c | 15 ++-------------
contrib/btree_gist/btree_oid.c | 10 ++--------
contrib/btree_gist/btree_text.c | 13 ++-----------
contrib/btree_gist/btree_time.c | 14 ++------------
contrib/btree_gist/btree_ts.c | 13 ++++---------
contrib/btree_gist/btree_uuid.c | 7 ++-----
21 files changed, 47 insertions(+), 185 deletions(-)