Determines if the style attributes of
new_match are a closer match for this than those of
old_match are, or if
old_match is null, determines if
new_match is a match
Approximate matching is done for weight and style; other style attributes must match exactly. Style attributes are all attributes other than family and size-related attributes. Approximate matching for style considers pango_style_oblique and pango_style_italic as matches, but not as good a match as when the styles are equal.
old_match must match this.
a `PangoFontDescription`, or null