pgsql: Fix two typos in xlogstats.h and xlogstats.c

Fix two typos in xlogstats.h and xlogstats.c Issue found while browsing this area of the code, introduced and copy-pasted around by 2258e76f90bf. Backpatch-through: 15 Branch -- master Details --- https://git.postgresql.org/pg/commitdiff/3a36543d7d08eef6496fe3511f4cf04cba14f572 Modifie

pgsql: test_bitmapset: Improve random function

test_bitmapset: Improve random function test_random_operations() did not check the result returned by bms_is_member() in its last phase, when checking that the contents of the bitmap match with what is expected. This was impacting the reliability of the function and the coverage it could provide.

pgsql: Clean up memory leakage that occurs in context callback function

Clean up memory leakage that occurs in context callback functions. An error context callback function might leak some memory into ErrorContext, since those functions are run with ErrorContext as current context. In the case where the elevel is ERROR, this is no problem since the code level that c