Rewrite some regression queries for option checks with COPY

Some queries in copy2 are there to check various option combinations,
and used "stdin" or "stdout" incompatible with the COPY TO or FROM
clauses combined with them, which was confusing.  This commit rewrites
these queries to use a compatible grammar.

The coverage of the tests is unchanged.  Like the original commit
451d116, backpatch down to 16 where these have been introduced.  A
follow-up commit will rely on this area of the tests for a bug fix.

Author: Joel Jacobson
Reviewed-by: Zhang Mingli
Discussion: https://postgr.es/m/65030d1d-5f90-4fa4-92eb-f5f50389858e@app.fastmail.com
Backpatch-through: 16

Author: michaelpq

src/test/regress/expected/copy2.out

@@ -86,36 +86,36 @@ ERROR:  conflicting or redundant options
 LINE 1: COPY x from stdin (log_verbosity default, log_verbosity verb...
                                                   ^
 -- incorrect options
-COPY x to stdin (format BINARY, delimiter ',');
+COPY x from stdin (format BINARY, delimiter ',');
 ERROR:  cannot specify DELIMITER in BINARY mode
-COPY x to stdin (format BINARY, null 'x');
+COPY x from stdin (format BINARY, null 'x');
 ERROR:  cannot specify NULL in BINARY mode
 COPY x from stdin (format BINARY, on_error ignore);
 ERROR:  only ON_ERROR STOP is allowed in BINARY mode
 COPY x from stdin (on_error unsupported);
 ERROR:  COPY ON_ERROR "unsupported" not recognized
 LINE 1: COPY x from stdin (on_error unsupported);
                            ^
-COPY x to stdin (format TEXT, force_quote(a));
+COPY x from stdin (format TEXT, force_quote(a));
 ERROR:  COPY FORCE_QUOTE requires CSV mode
 COPY x from stdin (format CSV, force_quote(a));
 ERROR:  COPY FORCE_QUOTE cannot be used with COPY FROM
-COPY x to stdout (format TEXT, force_not_null(a));
+COPY x from stdin (format TEXT, force_not_null(a));
 ERROR:  COPY FORCE_NOT_NULL requires CSV mode
-COPY x to stdin (format CSV, force_not_null(a));
+COPY x to stdout (format CSV, force_not_null(a));
 ERROR:  COPY FORCE_NOT_NULL cannot be used with COPY TO
-COPY x to stdout (format TEXT, force_null(a));
+COPY x from stdin (format TEXT, force_null(a));
 ERROR:  COPY FORCE_NULL requires CSV mode
-COPY x to stdin (format CSV, force_null(a));
+COPY x to stdout (format CSV, force_null(a));
 ERROR:  COPY FORCE_NULL cannot be used with COPY TO
-COPY x to stdin (format BINARY, on_error unsupported);
+COPY x to stdout (format BINARY, on_error unsupported);
 ERROR:  COPY ON_ERROR cannot be used with COPY TO
-LINE 1: COPY x to stdin (format BINARY, on_error unsupported);
-                                        ^
-COPY x to stdout (log_verbosity unsupported);
+LINE 1: COPY x to stdout (format BINARY, on_error unsupported);
+                                         ^
+COPY x from stdin (log_verbosity unsupported);
 ERROR:  COPY LOG_VERBOSITY "unsupported" not recognized
-LINE 1: COPY x to stdout (log_verbosity unsupported);
-                          ^
+LINE 1: COPY x from stdin (log_verbosity unsupported);
+                           ^
 COPY x from stdin with (reject_limit 1);
 ERROR:  COPY REJECT_LIMIT requires ON_ERROR to be set to IGNORE
 COPY x from stdin with (on_error ignore, reject_limit 0);

src/test/regress/sql/copy2.sql

@@ -70,18 +70,18 @@ COPY x from stdin (on_error ignore, on_error ignore);
 COPY x from stdin (log_verbosity default, log_verbosity verbose);
 
 -- incorrect options
-COPY x to stdin (format BINARY, delimiter ',');
-COPY x to stdin (format BINARY, null 'x');
+COPY x from stdin (format BINARY, delimiter ',');
+COPY x from stdin (format BINARY, null 'x');
 COPY x from stdin (format BINARY, on_error ignore);
 COPY x from stdin (on_error unsupported);
-COPY x to stdin (format TEXT, force_quote(a));
+COPY x from stdin (format TEXT, force_quote(a));
 COPY x from stdin (format CSV, force_quote(a));
-COPY x to stdout (format TEXT, force_not_null(a));
-COPY x to stdin (format CSV, force_not_null(a));
-COPY x to stdout (format TEXT, force_null(a));
-COPY x to stdin (format CSV, force_null(a));
-COPY x to stdin (format BINARY, on_error unsupported);
-COPY x to stdout (log_verbosity unsupported);
+COPY x from stdin (format TEXT, force_not_null(a));
+COPY x to stdout (format CSV, force_not_null(a));
+COPY x from stdin (format TEXT, force_null(a));
+COPY x to stdout (format CSV, force_null(a));
+COPY x to stdout (format BINARY, on_error unsupported);
+COPY x from stdin (log_verbosity unsupported);
 COPY x from stdin with (reject_limit 1);
 COPY x from stdin with (on_error ignore, reject_limit 0);