pgsql: Add TAP test to automate the equivalent of check_guc, take two

Add TAP test to automate the equivalent of check_guc, take two src/backend/utils/misc/check_guc is a script that cross-checks the consistency of the GUCs with postgresql.conf.sample, making sure that its format is in line with what guc.c has. It has never been run automatically, and has rotten ov

pgsql: Add TAP test to automate the equivalent of check_guc

Add TAP test to automate the equivalent of check_guc src/backend/utils/misc/check_guc is a script that cross-checks the consistency of the GUCs with postgresql.conf.sample, making sure that its format is in line with what guc.c has. It has never been run automatically, and has rotten over the yea