The problem is that deprecated syntax warnings were not being
suppressed when the stored routine is being parsed for the first
execution. It's doesn't make sense to print out deprecated
syntax warnings when the routine is being executed because this
kind of warning only matters when the routine is being created.

The solution is to suppress deprecated syntax warnings when
parsing the stored routine for loading into the cache (might
mean that the routine is being executed for the first time).


mysql-test/r/sp-error.result:
  Add test case result for Bug#21801
mysql-test/t/sp-error.test:
  Add test case for Bug#21801
sql/sp.cc:
  Implement a internal error handler to catch deprecated
  syntax warnings when loading a stored procedure into the
  cache.