Copy editing: fix a bunch of misspellings and poor wording.

99% of this is docs, but also a couple of comments.  No code changes.

Justin Pryzby

Discussion: https://postgr.es/m/20200919175804.GE30557@telsasoft.com

src/backend/access/gin/README

@@ -413,7 +413,7 @@ leftmost leaf of the tree.
 Deletion algorithm keeps exclusive locks on left siblings of pages comprising
 currently investigated path.  Thus, if current page is to be removed, all
 required pages to remove both downlink and rightlink are already locked.  That
-evades potential right to left page locking order, which could deadlock with
+avoids potential right to left page locking order, which could deadlock with
 concurrent stepping right.
 
 A search concurrent to page deletion might already have read a pointer to the

src/backend/utils/adt/jsonpath_exec.c

@@ -35,7 +35,7 @@
  * executeItemOptUnwrapTarget() function have 'unwrap' argument, which indicates
  * whether unwrapping of array is needed.  When unwrap == true, each of array
  * members is passed to executeItemOptUnwrapTarget() again but with unwrap == false
- * in order to evade subsequent array unwrapping.
+ * in order to avoid subsequent array unwrapping.
  *
  * All boolean expressions (predicates) are evaluated by executeBoolItem()
  * function, which returns tri-state JsonPathBool.  When error is occurred

src/test/regress/expected/partition_join.out

@@ -4567,7 +4567,7 @@ ANALYZE plt3_adv;
 -- This tests that when merging partitions from plt1_adv and plt2_adv in
 -- merge_list_bounds(), process_outer_partition() returns an already-assigned
 -- merged partition when re-called with plt1_adv_p1 for the second list value
--- '0001' of that partitin
+-- '0001' of that partition
 EXPLAIN (COSTS OFF)
 SELECT t1.a, t1.c, t2.a, t2.c, t3.a, t3.c FROM (plt1_adv t1 LEFT JOIN plt2_adv t2 ON (t1.c = t2.c)) FULL JOIN plt3_adv t3 ON (t1.c = t3.c) WHERE coalesce(t1.a, 0) % 5 != 3 AND coalesce(t1.a, 0) % 5 != 4 ORDER BY t1.c, t1.a, t2.a, t3.a;
                                           QUERY PLAN                                           

src/test/regress/sql/partition_join.sql

@@ -1090,7 +1090,7 @@ ANALYZE plt3_adv;
 -- This tests that when merging partitions from plt1_adv and plt2_adv in
 -- merge_list_bounds(), process_outer_partition() returns an already-assigned
 -- merged partition when re-called with plt1_adv_p1 for the second list value
--- '0001' of that partitin
+-- '0001' of that partition
 EXPLAIN (COSTS OFF)
 SELECT t1.a, t1.c, t2.a, t2.c, t3.a, t3.c FROM (plt1_adv t1 LEFT JOIN plt2_adv t2 ON (t1.c = t2.c)) FULL JOIN plt3_adv t3 ON (t1.c = t3.c) WHERE coalesce(t1.a, 0) % 5 != 3 AND coalesce(t1.a, 0) % 5 != 4 ORDER BY t1.c, t1.a, t2.a, t3.a;
 SELECT t1.a, t1.c, t2.a, t2.c, t3.a, t3.c FROM (plt1_adv t1 LEFT JOIN plt2_adv t2 ON (t1.c = t2.c)) FULL JOIN plt3_adv t3 ON (t1.c = t3.c) WHERE coalesce(t1.a, 0) % 5 != 3 AND coalesce(t1.a, 0) % 5 != 4 ORDER BY t1.c, t1.a, t2.a, t3.a;