GitLab

Found by UBSan.

* src/nsfns.m (ns_set_foreground_color, ns_set_background_color):
* src/nsimage.m (getPixelAtX:Y:):
* src/nsterm.m (ns_color_index_to_rgba): Add explicit casts to avoid
undefined behavior when left-shifting beyond the bounds of the int
type.

* src/macfont.m (METRICS_VALUE): Add explicit casts to avoid undefined
behavior when left-shifting a negative value.