[Ada] Fix exit status of GNAT.Expect.Close call on running process

[Ada] Fix exit status of GNAT.Expect.Close call on running process

gcc/ada/

	* expect.c (__gnat_waitpid): Use macros WIFEXITED, WEXITSTATUS,
	WIFSIGNALED, WTERMSIG, WIFSTOPPED, WSTOPSIG to get exit status
	or signal that caused the child process to terminate/stop.  Do
	not process exit status in case of error in waitpid call.
	* adaint.c (__gnat_kill): Use of GenerateConsoleCtrlEvent is
	removed in Windows variant as it actually is not working and was
	terminating the calling process.  Set signal number into exit
	code parameter of TerminateProcess to work the same like in
	Linux.