Fixes for running maria-recovery*.test and maria-purge.test under

Windows.


include/my_dbug.h:
  a DBUG expression to force a flush of the trace file then an abort of the process
mysql-test/include/wait_until_connected_again.inc:
  mysqladmin waits for pid file to be gone only under Unix; so
  maria_empty_logs.inc cannot wait for mysqld to be gone, so
  wait_until_connected_again.inc may send its "show status" to a 
  not-yet-dead server hence the 1053 error ("server shutdown in progress")
mysys/my_thr_init.c:
  overload abort() under Windows, to not have an annoying CRT popup
  ("ignore/abort/retry" buttons) each time a test intentionally
  crashes mysqld
sql/handler.cc:
  use new expression
sql/log.cc:
  use new expression
sql/mysql_priv.h:
  use new expression
storage/maria/ha_maria.cc:
  use new expression
storage/maria/ma_blockrec.c:
  use new expression
storage/maria/ma_check.c:
  use new expression
storage/maria/ma_checkpoint.c:
  use new expression
storage/maria/ma_control_file.c:
  Can't yet lock control file under Windows (test suite problems,
  plus concerns about stray lock preventing a fast restart after crash).
storage/maria/ma_loghandler.c:
  A file which should be closed, otherwise translog_purge() (the caller)
  cannot delete logs.

include/my_dbug.h

@@ -85,6 +85,7 @@ extern  void _db_force_flush();
 #define DEBUGGER_OFF                    do { _dbug_on_= 0; } while(0)
 #define DEBUGGER_ON                     do { _dbug_on_= 1; } while(0)
 #define IF_DBUG(A) A
+#define DBUG_ABORT()       ((void)fflush(DBUG_FILE), abort())
 #else						/* No debugger */
 
 #define DBUG_ENTER(a1)
@@ -114,6 +115,7 @@ extern  void _db_force_flush();
 #define DEBUGGER_OFF                    do { } while(0)
 #define DEBUGGER_ON                     do { } while(0)
 #define IF_DBUG(A)
+#define DBUG_ABORT()                    ((void)(0))
 #endif
 #ifdef	__cplusplus
 }