Added the code processing on expressions for applying
  multiple equalities.
sql_select.cc:
  Post-merge fixes for Item_equal patch.
  Added the code processing on expressions for applying
  multiple equalities.
Many files:
  Post-merge fixes for Item_equal patch.
item_cmpfunc.cc:
  Post-merge fixes for Item_equal patch.
  Fixed a problem when an equality field=const cannot be applied to
  the predicate P(field,c) for constant propagation as a conversion
  of field is needed.
item.h, item.cc:
  Fixed a problem when an equality field=const cannot be applied to
  the predicate P(field,c) for constant propagation as a conversion
  of field is needed.


mysql-test/r/func_test.result:
  Post-merge fixes for Item_equal patch.
mysql-test/r/index_merge.result:
  Post-merge fixes for Item_equal patch.
mysql-test/r/join_nested.result:
  Post-merge fixes for Item_equal patch.
mysql-test/r/range.result:
  Post-merge fixes for Item_equal patch.
sql/item.cc:
  Fixed a problem when an equality field=const cannot be applied to
  the predicate P(field,c) for constant propagation as a conversion
  of field is needed.
sql/item.h:
  Fixed a problem when an equality field=const cannot be applied to
  the predicate P(field,c) for constant propagation as a conversion
  of field is needed.
sql/item_cmpfunc.cc:
  Post-merge fixes for Item_equal patch.
  Fixed a problem when an equality field=const cannot be applied to
  the predicate P(field,c) for constant propagation as a conversion
  of field is needed.
sql/opt_range.cc:
  Post-merge fixes for Item_equal patch.
sql/sql_select.cc:
  Post-merge fixes for Item_equal patch.
  Added the code processing on expressions for applying
  multiple equalities.
sql/sql_select.h:
  Added the code processing on expressions for applying
  multiple equalities.
sql/table.h:
  Added the code processing on expressions for applying
  multiple equalities.