wow64win: Fix UNICODE_STRING thunking in wow64_NtUserRegisterWindowMessage.
The function was passing a 32-bit UNICODE_STRING
pointer directly to the 64-bit
function, causing string corruption. Use the unicode_str_32to64()
helper like other
similar functions.
This fixes 32-bit .NET Framework applications failing to create windows, such as dnSpyEx v6.5.1 (x86), when using a new-style WoW64 build.
Fixes: 73f4aeb2