patch 8.0.0899: function name mch_stop_job() is confusing

Problem:    Function name mch_stop_job() is confusing.
Solution:   Rename to mch_signal_job().
diff --git a/src/terminal.c b/src/terminal.c
index e22f7bc..b22cc1a 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -1143,7 +1143,7 @@
 	    /* We don't know if the job can handle CTRL-C itself or not, this
 	     * may kill the shell instead of killing the command running in the
 	     * shell. */
-	    mch_stop_job(curbuf->b_term->tl_job, (char_u *)"quit");
+	    mch_signal_job(curbuf->b_term->tl_job, (char_u *)"quit");
 #endif
 
 	if (c == (termkey == 0 ? Ctrl_W : termkey) || c == Ctrl_BSL)
@@ -2735,7 +2735,7 @@
 		break;
 	}
 	if (part < PART_COUNT && mch_report_winsize(fd, rows, cols) == OK)
-	    mch_stop_job(term->tl_job, (char_u *)"winch");
+	    mch_signal_job(term->tl_job, (char_u *)"winch");
     }
 }