Add SQL_ASCII test case

src/test/regress/expected/sql_ascii.out

+drop table computer_terms;
+ERROR:  Relation 'computer_terms' does not exist
+create table computer_terms(term text, category text, comments char(16));
+create index computer_terms_index1 on computer_terms using btree(term);
+create index computer_terms_index2 on computer_terms using btree(category);
+insert into computer_terms values('computer display', 'X-A01-Y', 'a comment 1');
+insert into computer_terms values('computer graphics', 'T-B01-Y', 'a comment 2');
+insert into computer_terms values('computer programmer', 'S-Z01-Y', 'a comment 3');
+vacuum computer_terms;
+select * from computer_terms;
+        term         | category |     comments     
+---------------------+----------+------------------
+ computer display    | X-A01-Y  | a comment 1     
+ computer graphics   | T-B01-Y  | a comment 2     
+ computer programmer | S-Z01-Y  | a comment 3     
+(3 rows)
+
+select * from computer_terms where category = 'X-A01-Y';
+       term       | category |     comments     
+------------------+----------+------------------
+ computer display | X-A01-Y  | a comment 1     
+(1 row)
+
+select * from computer_terms where category ~* 'x-a01-y';
+       term       | category |     comments     
+------------------+----------+------------------
+ computer display | X-A01-Y  | a comment 1     
+(1 row)
+
+select * from computer_terms where category like '_-A01-_';
+       term       | category |     comments     
+------------------+----------+------------------
+ computer display | X-A01-Y  | a comment 1     
+(1 row)
+
+select * from computer_terms where category like '_-A%';
+       term       | category |     comments     
+------------------+----------+------------------
+ computer display | X-A01-Y  | a comment 1     
+(1 row)
+
+select * from computer_terms where term ~ 'computer [dg]';
+       term        | category |     comments     
+-------------------+----------+------------------
+ computer display  | X-A01-Y  | a comment 1     
+ computer graphics | T-B01-Y  | a comment 2     
+(2 rows)
+
+select * from computer_terms where term ~* 'computer [DG]';
+       term        | category |     comments     
+-------------------+----------+------------------
+ computer display  | X-A01-Y  | a comment 1     
+ computer graphics | T-B01-Y  | a comment 2     
+(2 rows)
+
+select *,character_length(term) from computer_terms;
+        term         | category |     comments     | length 
+---------------------+----------+------------------+--------
+ computer display    | X-A01-Y  | a comment 1      |     16
+ computer graphics   | T-B01-Y  | a comment 2      |     17
+ computer programmer | S-Z01-Y  | a comment 3      |     19
+(3 rows)
+
+select *,octet_length(term) from computer_terms;
+        term         | category |     comments     | octet_length 
+---------------------+----------+------------------+--------------
+ computer display    | X-A01-Y  | a comment 1      |           16
+ computer graphics   | T-B01-Y  | a comment 2      |           17
+ computer programmer | S-Z01-Y  | a comment 3      |           19
+(3 rows)
+
+select *,position('s' in term) from computer_terms;
+        term         | category |     comments     | strpos 
+---------------------+----------+------------------+--------
+ computer display    | X-A01-Y  | a comment 1      |     12
+ computer graphics   | T-B01-Y  | a comment 2      |     17
+ computer programmer | S-Z01-Y  | a comment 3      |      0
+(3 rows)
+
+select *,substring(term from 10 for 4) from computer_terms;
+        term         | category |     comments     | substr 
+---------------------+----------+------------------+--------
+ computer display    | X-A01-Y  | a comment 1      | disp
+ computer graphics   | T-B01-Y  | a comment 2      | grap
+ computer programmer | S-Z01-Y  | a comment 3      | prog
+(3 rows)
+