Tests show that IsThemePartDefined() doesn't use state ID to search parts. If a part of any state is
present, the part is considered as defined. For example, disabled state of part EditText of class
Edit is present in theme files but there is no default state for part EditText. So
IsThemePartDefined(theme, EP_EDITTEXT, 0) failed previously and it should succeed.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=52581Signed-off-by: Zhiyi Zhang <zzhang@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>