- Introduce ifdefs so we can control when to use #pragma interface on cygwin


include/my_global.h:
  Turn on use of #pragma implementation and #pragma interface if compiled with GCC and platform != Cygwin
include/raid.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/examples/ha_archive.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/examples/ha_example.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/field.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/ha_berkeley.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/ha_blackhole.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/ha_heap.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/ha_innodb.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/ha_isam.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/ha_isammrg.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/ha_myisam.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/ha_myisammrg.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/ha_ndbcluster.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/handler.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/item.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/item_cmpfunc.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/item_func.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/item_geofunc.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/item_strfunc.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/item_subselect.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/item_sum.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/item_timefunc.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/opt_range.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/procedure.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/protocol.h:
  replace __GNUC__ with USE_PRAGMA_IMPLEMENTATION
sql/set_var.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/sql_class.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/sql_list.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/sql_select.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/sql_string.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/sql_udf.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE
sql/tztime.h:
  replace __GNUC__ with USE_PRAGMA_INTERFACE