Disabled the GOTO feature. (It's non-standard and undocumented.)

We want to have the defacto standard syntax for labels ("L:" instead of "label L;"),
and fix some known bugs, before we enable this again.
The code is left intact (#ifdef'ed SP_GOTO) and the test cases are kept in
sp-goto.test, for the future...

mysql-test/t/sp-error.test

@@ -84,7 +84,7 @@ show create procedure foo|
 --error 1305
 show create function foo|
 
-# LEAVE/ITERATE/GOTO with no match
+# LEAVE/ITERATE with no match
 --error 1308
 create procedure foo()
 foo: loop
@@ -100,47 +100,6 @@ create procedure foo()
 foo: begin
   iterate foo;
 end|
---error 1308
-create procedure foo()
-begin
-  goto foo;
-end|
---error 1308
-create procedure foo()
-begin
-  begin
-    label foo;
-  end;
-  goto foo;
-end|
---error 1308
-create procedure foo()
-begin
-  goto foo;
-  begin
-    label foo;
-  end;
-end|
---error 1308
-create procedure foo()
-begin
-  begin
-    goto foo;
-  end;
-  begin
-    label foo;
-  end;
-end|
---error 1308
-create procedure foo()
-begin
-  begin
-    label foo;
-  end;
-  begin
-    goto foo;
-  end;
-end|
 
 # Redefining label
 --error 1309
@@ -398,18 +357,6 @@ begin
   declare c cursor for select * from t1;
 end|
 
---error 1358
-create procedure p()
-begin
-  declare continue handler for sqlexception
-    begin
-      goto L1;
-    end;
-
-  select field from t1;
-  label L1;
-end|
-
 # Check in and inout arguments.
 --disable_warnings
 drop procedure if exists p|