view that has Group By
      
When SELECT'ing from a view that mentions another,
materialized, view, access was being denied. The issue was
resolved by lifting a special case which avoided such access
checking in check_single_table_access. In the past, this was
necessary since if such a check were performed, the error
message would be downgraded to a warning in the case of SHOW
CREATE VIEW. The downgrading of errors was meant to handle
only that scenario, but could not distinguish the two as it
read only the error messages.
      
The special case was needed in the fix of bug no 36086.
Before that, views were confused with derived tables.
      
After bug no 35996 was fixed, the manipulation of errors
during SHOW CREATE VIEW execution is not dependent on the
actual error messages in the queue, it rather looks at the
actual cause of the error and takes appropriate
action. Hence the aforementioned special case is now
superfluous and the bug is fixed.


mysql-test/r/view_grant.result:
  Bug#46019: Test result.
mysql-test/t/view_grant.test:
  Bug#46019: Test case.
sql/sql_parse.cc:
  Bug#46019: fix.