patch 8.2.0765: In the GUI can't use all the modifiers.

Problem:    In the GUI can't use all the modifiers. (Andri Möll)
Solution:   Do not apply Alt/Meta early, do it later like with the terminal.
            Avoid the Motif test from crashing.
diff --git a/src/gui_mac.c b/src/gui_mac.c
index b37d3f5..b048375 100644
--- a/src/gui_mac.c
+++ b/src/gui_mac.c
@@ -2168,9 +2168,9 @@
 	    // taken liberally from gui_w48.c
 	    key_char = simplify_key(key_char, (int *)&vimModifiers);
 
-	    // Interpret META, include SHIFT, etc.
+	    // Unify modifiers somewhat.  No longer use ALT to set the 8th bit.
 	    key_char = extract_modifiers(key_char, (int *)&vimModifiers,
-		    TRUE, NULL);
+								  FALSE, NULL);
 	    if (key_char == CSI)
 		key_char = K_CSI;