Make all ereport() calls within gram.y provide error locations.

This patch responds to a comment that I (tgl) made in the
discussion leading up to 774171c4f, that really all errors
occurring during raw parsing should provide error cursors.
Syntax errors reported by Bison will have one, and most of
the handwritten ereport's in gram.y already provide one,
but there were a few stragglers.

(It is not claimed that this handles every failure reachable
during raw parsing --- out-of-memory is an obvious exception.
But this makes a good start on cases that are likely to occur.)

While we're at it, clean up the reported positions for errors
associated with LIMIT/OFFSET clauses.  Previously we were
relying on applying exprLocation() to the contained expressions,
but that leads to slightly odd cursor placement, e.g.

regression=# (select * from foo limit 10) limit 10;
ERROR:  multiple LIMIT clauses not allowed
LINE 1: (select * from foo limit 10) limit 10;
                                           ^

We can afford to keep a little more state in the transient
SelectLimit structs in order to make that better.

Jian He and Tom Lane (extracted from a larger patch by Jian,
with some additional work by me)

Discussion: https://postgr.es/m/CACJufxEmONE3P2En=jopZy1m=cCCUs65M4+1o52MW5og9oaUPA@mail.gmail.com

3 files changed, 10 insertions, 0 deletions

diff --git a/src/test/regress/expected/create_table.out b/src/test/regress/expected/create_table.out
index c45e02d42f9..57a24050ab8 100644
--- a/src/test/regress/expected/create_table.out
+++ b/src/test/regress/expected/create_table.out
@@ -198,6 +198,8 @@ CREATE TABLE partitioned (
     a int
 ) PARTITION BY MAGIC (a);
 ERROR:  unrecognized partitioning strategy "magic"
+LINE 3: ) PARTITION BY MAGIC (a);
+                       ^
 -- specified column must be present in the table
 CREATE TABLE partitioned (
 	a int
diff --git a/src/test/regress/expected/limit.out b/src/test/regress/expected/limit.out
index a2cd0f9f5b8..f4267c002d7 100644
--- a/src/test/regress/expected/limit.out
+++ b/src/test/regress/expected/limit.out
@@ -624,11 +624,15 @@ SELECT  thousand
 		FROM onek WHERE thousand < 5
 		ORDER BY thousand FETCH FIRST 1 ROW WITH TIES FOR UPDATE SKIP LOCKED;
 ERROR:  SKIP LOCKED and WITH TIES options cannot be used together
+LINE 3:   ORDER BY thousand FETCH FIRST 1 ROW WITH TIES FOR UPDATE S...
+                                              ^
 -- should fail
 SELECT ''::text AS two, unique1, unique2, stringu1
 		FROM onek WHERE unique1 > 50
 		FETCH FIRST 2 ROW WITH TIES;
 ERROR:  WITH TIES cannot be specified without ORDER BY clause
+LINE 3:   FETCH FIRST 2 ROW WITH TIES;
+                            ^
 -- test ruleutils
 CREATE VIEW limit_thousand_v_1 AS SELECT thousand FROM onek WHERE thousand < 995
 		ORDER BY thousand FETCH FIRST 5 ROWS WITH TIES OFFSET 10;
diff --git a/src/test/regress/expected/sqljson.out b/src/test/regress/expected/sqljson.out
index 70721c9a5ad..435d61dd4a3 100644
--- a/src/test/regress/expected/sqljson.out
+++ b/src/test/regress/expected/sqljson.out
@@ -337,6 +337,8 @@ LINE 1: SELECT JSON_OBJECT(RETURNING text FORMAT JSON ENCODING UTF8)...
                                           ^
 SELECT JSON_OBJECT(RETURNING text FORMAT JSON ENCODING INVALID_ENCODING);
 ERROR:  unrecognized JSON encoding: invalid_encoding
+LINE 1: ...T JSON_OBJECT(RETURNING text FORMAT JSON ENCODING INVALID_EN...
+                                                             ^
 SELECT JSON_OBJECT(RETURNING bytea);
  json_object 
 -------------
@@ -620,6 +622,8 @@ LINE 1: SELECT JSON_ARRAY(RETURNING text FORMAT JSON ENCODING UTF8);
                                          ^
 SELECT JSON_ARRAY(RETURNING text FORMAT JSON ENCODING INVALID_ENCODING);
 ERROR:  unrecognized JSON encoding: invalid_encoding
+LINE 1: ...CT JSON_ARRAY(RETURNING text FORMAT JSON ENCODING INVALID_EN...
+                                                             ^
 SELECT JSON_ARRAY(RETURNING bytea);
  json_array 
 ------------