Predefined locale values are missing

The official docs for [`GetLocaleInfoW()`](https://learn.microsoft.com/en-us/windows/win32/api/winnls/nf-winnls-getlocaleinfow) list a number of constants for the first parameter that aren't in the `windows` crate.

Maybe it's because the top of the page says [`GetLocaleInfoEx()`](https://learn.microsoft.com/en-us/windows/desktop/api/winnls/nf-winnls-getlocaleinfoex) should be used instead (by why is the old function available then?). But for that new function, I also found the missing value `LOCALE_NAME_USER_DEFAULT`.

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BTW: The official docs for [`GetLocaleInfoEx()`](https://learn.microsoft.com/en-us/windows/desktop/api/winnls/nf-winnls-getlocaleinfoex) also contain an easily misunderstood statement, or one that you first have to think of as a documentation error:

> The buffer that receives the value must be at least the length of a DWORD value, which is 2.

By "2", they mean 2 wide chars, so 4 bytes.

Start by comparing the documented constants for GetLocaleInfoW() and GetLocaleInfoEx() with the Windows metadata generated by this repository, paying particular attention to LOCALE_NAME_USER_DEFAULT. Confirm which predefined locale values are absent and verify that the corrected generated metadata exposes them; the buffer-size wording is a separate documentation concern.

Written by the indexing model from the issue text.