patch 8.0.0913: MS-Windows: CTRL-C kills shell in terminal window

Problem:    MS-Windows: CTRL-C kills shell in terminal window instead of the
            command running in the shell.
Solution:   Make CTRL-C only send a CTRL_C_EVENT and have CTRL-BREAK kill the
            job. (partly by Yasuhiro Matsumoto, closes #1962)
diff --git a/src/gui_w32.c b/src/gui_w32.c
index a91e071..863975c 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -1840,6 +1840,7 @@
 	{
 	    trash_input_buf();
 	    got_int = TRUE;
+	    ctrl_break_was_pressed = TRUE;
 	    string[0] = Ctrl_C;
 	    add_to_input_buf(string, 1);
 	}