from stored procedure. 

Problem: we replace all references to local variables in stored procedures     
with NAME_CONST(name, value) logging to the binary log. However, if the
value's collation differs we might get an 'illegal mix of collation'           
error as we don't pass the collation to the function.

Fix: pass the value's collation to NAME_CONST().

Note: actually we should pass to NAME_CONST() the value's derivation as well.
It's impossible without the parser modifying. Now we always set the 
derivation to DERIVATION_IMPLICIT, the same as local variables have.


mysql-test/r/binlog.result:
  Fix for bug#39182: Binary log producing incompatible character set query
  from stored procedure.
    - test result.
mysql-test/r/ctype_cp932_binlog.result:
  Fix for bug#39182: Binary log producing incompatible character set query
  from stored procedure.
    - results adjusted.
mysql-test/r/rpl_sp.result:
  Fix for bug#39182: Binary log producing incompatible character set query
  from stored procedure.
    - results adjusted.
mysql-test/t/binlog.test:
  Fix for bug#39182: Binary log producing incompatible character set query
  from stored procedure.
    - test case.
sql/item.cc:
  Fix for bug#39182: Binary log producing incompatible character set query
  from stored procedure.
    - allow NAME_CONST() to get _charset'foo' COLLATE 'bar' strings
  (see Item_func_set_collation).
sql/sp_head.cc:
  Fix for bug#39182: Binary log producing incompatible character set query
  from stored procedure. 
    - pass the value's collation to NAME_CONST().