do not force CONNECTION_ID(), FOUND_ROWS(), PI(), CURRENT_USER(),

and VERSION() to be uppercase in e.g. "select pi()"

mysql-test/r/func_math.result

@@ -36,7 +36,7 @@ select rand(999999),rand();
 rand(999999)	rand()
 0.014231365187309	0.028870999839968
 select pi(),sin(pi()/2),cos(pi()/2),abs(tan(pi())),cot(1),asin(1),acos(0),atan(1);
-PI()	sin(pi()/2)	cos(pi()/2)	abs(tan(pi()))	cot(1)	asin(1)	acos(0)	atan(1)
+pi()	sin(pi()/2)	cos(pi()/2)	abs(tan(pi()))	cot(1)	asin(1)	acos(0)	atan(1)
 3.141593	1.000000	0.000000	0.000000	0.64209262	1.570796	1.570796	0.785398
 select degrees(pi()),radians(360);
 degrees(pi())	radians(360)

mysql-test/r/select_found.result

@@ -12,43 +12,43 @@ a	b
 7	7
 8	9
 select found_rows();
-FOUND_ROWS()
+found_rows()
 8
 select SQL_CALC_FOUND_ROWS * from t1 limit 1;
 a	b
 1	2
 select found_rows();
-FOUND_ROWS()
+found_rows()
 8
 select SQL_BUFFER_RESULT SQL_CALC_FOUND_ROWS * from t1 limit 1;
 a	b
 1	2
 select found_rows();
-FOUND_ROWS()
+found_rows()
 8
 select SQL_CALC_FOUND_ROWS * from t1 order by b desc limit 1;
 a	b
 8	9
 select found_rows();
-FOUND_ROWS()
+found_rows()
 8
 select SQL_CALC_FOUND_ROWS distinct b from t1 limit 1;
 b
 2
 select found_rows();
-FOUND_ROWS()
+found_rows()
 6
 select SQL_CALC_FOUND_ROWS b,count(*) as c from t1 group by b order by c desc limit 1;
 b	c
 5	3
 select found_rows();
-FOUND_ROWS()
+found_rows()
 6
 select SQL_CALC_FOUND_ROWS * from t1 left join t1 as t2 on (t1.b=t2.a) limit 2,1;
 a	b	a	b
 3	5	5	5
 select found_rows();
-FOUND_ROWS()
+found_rows()
 8
 drop table t1;
 create table t1 (a int not null primary key);

mysql-test/r/union.result

@@ -94,7 +94,7 @@ a	b
 1	a
 2	b
 select found_rows();
-FOUND_ROWS()
+found_rows()
 6
 explain select a,b from t1 union all select a,b from t2;
 table	type	possible_keys	key	key_len	ref	rows	Extra

sql/item_create.cc

@@ -77,7 +77,7 @@ Item *create_func_connection_id(void)
 {
   THD *thd=current_thd;
   thd->safe_to_cache_query=0;
-  return new Item_int("CONNECTION_ID()",(longlong) thd->thread_id,10);
+  return new Item_int(NullS,(longlong) thd->thread_id,10);
 }
 
 Item *create_func_conv(Item* a, Item *b, Item *c)
@@ -145,7 +145,7 @@ Item *create_func_found_rows(void)
 {
   THD *thd=current_thd;
   thd->safe_to_cache_query=0;
-  return new Item_int("FOUND_ROWS()",(longlong) thd->found_rows(),21);
+  return new Item_int(NullS,(longlong) thd->found_rows(),21);
 }
 
 Item *create_func_from_days(Item* a)
@@ -283,7 +283,7 @@ Item *create_func_period_diff(Item* a, Item *b)
 
 Item *create_func_pi(void)
 {
-  return new Item_real("PI()",M_PI,6,8);
+  return new Item_real(NullS,M_PI,6,8);
 }
 
 Item *create_func_pow(Item* a, Item *b)
@@ -299,7 +299,7 @@ Item *create_func_current_user()
 
   length= (uint) (strxmov(buff, thd->priv_user, "@", thd->host_or_ip, NullS) -
 		  buff);
-  return new Item_string("CURRENT_USER()", thd->memdup(buff, length), length);
+  return new Item_string(NullS, thd->memdup(buff, length), length);
 }
 
 Item *create_func_quarter(Item* a)
@@ -405,7 +405,7 @@ Item *create_func_ucase(Item* a)
 
 Item *create_func_version(void)
 {
-  return new Item_string("VERSION()",server_version, strlen(server_version));
+  return new Item_string(NullS,server_version, strlen(server_version));
 }
 
 Item *create_func_weekday(Item* a)