patch 7.4.2222

Problem:    Sourcing a script where a character has 0x80 as a second byte does
            not work. (Filipe L B Correia)
Solution:   Turn 0x80 into K_SPECIAL KS_SPECIAL KE_FILLER. (Christian
            Brabandt, closes #728)  Add a test case.

src/misc1.c

@@ -3416,7 +3416,7 @@ get_keystroke(void)
 	if (n > 0)
 	{
 	    /* Replace zero and CSI by a special key code. */
-	    n = fix_input_buffer(buf + len, n, FALSE);
+	    n = fix_input_buffer(buf + len, n);
 	    len += n;
 	    waited = 0;
 	}