Added support for VISIBLE attribute for indexes in CREATE TABLE

MDEV-22199 Add VISIBLE attribute for indexes in CREATE TABLE

This was done to make it easier to read in dumps from MySQL 8.0 generated
with MySQL workbench

mysql-test/main/create.result

@@ -2012,3 +2012,5 @@ CREATE TABLE t1 ( id1 INT, id2 INT, CONSTRAINT `foo` PRIMARY KEY (id1), CONSTRAI
 Warnings:
 Warning	1280	Name 'foo' ignored for PRIMARY key.
 DROP TABLE t1;
+CREATE TABLE t1 (id1 INT, id2 INT, primary key (id1), unique index (id2) visible);
+drop table t1;

mysql-test/main/create.test

@@ -1873,3 +1873,9 @@ drop table t1;
 CREATE TABLE t1 ( id1 INT, id2 INT, CONSTRAINT `foo` PRIMARY KEY (id1), CONSTRAINT `bar` UNIQUE KEY(id2));
 DROP TABLE t1;
 
+#
+# MDEV-22199 Add VISIBLE option for indexes in create table
+#
+
+CREATE TABLE t1 (id1 INT, id2 INT, primary key (id1), unique index (id2) visible);
+drop table t1;

mysql-test/suite/perfschema/r/start_server_low_digest_sql_length.result

@@ -8,5 +8,5 @@ SELECT 1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1
 ####################################
 SELECT event_name, digest, digest_text, sql_text FROM events_statements_history_long;
 event_name	digest	digest_text	sql_text
-statement/sql/select	230fd11f009a87fecbb87c9fc7361475	SELECT ? + ? + 	SELECT ...
+statement/sql/select	beb5bd93b7e8c45bc5cb6060804988e8	SELECT ? + ? + 	SELECT ...
 statement/sql/truncate	faf6cefb662b443f05e97b5c5ab14a59	TRUNCATE TABLE 	truncat...

sql/lex.h

@@ -43,6 +43,9 @@ SYM_GROUP sym_group_rtree= {"RTree keys", "HAVE_RTREE_KEYS"};
   NOTE! The symbol tables should be the same regardless of what features
   are compiled into the server. Don't add ifdef'ed symbols to the
   lists
+  NOTE!!
+  If you add or delete symbols from this file, you must also update results for
+  the perfschema.start_server_low_digest_sql_length test!
 */
 
 static SYMBOL symbols[] = {
@@ -174,7 +177,7 @@ static SYMBOL symbols[] = {
   { "DAY_MICROSECOND",	SYM(DAY_MICROSECOND_SYM)},
   { "DAY_MINUTE",	SYM(DAY_MINUTE_SYM)},
   { "DAY_SECOND",	SYM(DAY_SECOND_SYM)},
-  { "DEALLOCATE",       SYM(DEALLOCATE_SYM)},     
+  { "DEALLOCATE",       SYM(DEALLOCATE_SYM)},
   { "DEC",		SYM(DECIMAL_SYM)},
   { "DECIMAL",		SYM(DECIMAL_SYM)},
   { "DECLARE",          SYM(DECLARE_MARIADB_SYM)},
@@ -705,6 +708,7 @@ static SYMBOL symbols[] = {
   { "VIA",              SYM(VIA_SYM)},
   { "VIEW",		SYM(VIEW_SYM)},
   { "VIRTUAL",          SYM(VIRTUAL_SYM)},
+  { "VISIBLE",          SYM(VISIBLE_SYM)},
   { "VERSIONING",       SYM(VERSIONING_SYM)},
   { "WAIT",		SYM(WAIT_SYM)},
   { "WARNINGS",		SYM(WARNINGS)},
@@ -713,7 +717,7 @@ static SYMBOL symbols[] = {
   { "WHEN",		SYM(WHEN_SYM)},
   { "WHERE",		SYM(WHERE)},
   { "WHILE",            SYM(WHILE_SYM)},
-  { "WINDOW",           SYM(WINDOW_SYM)}, 
+  { "WINDOW",           SYM(WINDOW_SYM)},
   { "WITH",		SYM(WITH)},
   { "WITHIN",   SYM(WITHIN)},
   { "WITHOUT",          SYM(WITHOUT)},

sql/sql_yacc.yy

@@ -1125,6 +1125,7 @@ End SQL_MODE_ORACLE_SPECIFIC */
 %token  <kwd>  VERSIONING_SYM                /* SQL-2011-R */
 %token  <kwd>  VIA_SYM
 %token  <kwd>  VIEW_SYM                      /* SQL-2003-N */
+%token  <kwd>  VISIBLE_SYM                   /* MySQL 8.0 */
 %token  <kwd>  VIRTUAL_SYM
 %token  <kwd>  WAIT_SYM
 %token  <kwd>  WARNINGS
@@ -6997,6 +6998,10 @@ all_key_opt:
          }
         | COMMENT_SYM TEXT_STRING_sys
           { Lex->last_key->key_create_info.comment= $2; }
+        | VISIBLE_SYM
+          {
+            /* This is mainly for MySQL 8.0 compatiblity */
+          }
         | IDENT_sys equal TEXT_STRING_sys
           {
             if (unlikely($3.length > ENGINE_OPTION_MAX_LENGTH))
@@ -15796,6 +15801,7 @@ keyword_sp_var_and_label:
         | VERSIONING_SYM
         | VIEW_SYM
         | VIRTUAL_SYM
+        | VISIBLE_SYM
         | VALUE_SYM
         | WARNINGS
         | WAIT_SYM