## Purpose
Add a stub for RpcGetAuthorizationContextForClient function into rpcrt4, according to https://docs.microsoft.com/en-us/windows/win32/api/rpcasync/nf-rpcasync-rpcgetauthorizationcontextforclient (but with Wine-specific diffs in the syntax, according to the code guidelines: https://wiki.winehq.org/Submitting_Patches#Code_guidelines, since we're syncing rpcrt4 with Wine). Required by MS Winlogon with also Win32 subsystem and some other dlls replaced (aka ROS-Frankenstein), so after my changes it doesn't fail with our rpcrt4.dll at the system startup.
I think I also need to submit a patch in Wine, but it is a bit problematically to reproduce this error there, since Wine has no even winlogon.exe, and launching MS Winlogon in pair with profmap.dll, causes the crash due to unimplemented RtlSetProcessIsCritical function in ntdll (which is completely different than our). Ftr, our ntdll already has it implemented: https://git.reactos.org/?p=reactos.git;a=blob;f=sdk/lib/rtl/process.c;hb=67c78d88c885ca92c72e2bcf59ddcf1d429096b1#l453 But with MS ntdll.dll, as far as I know, Wine will not work.
JIRA issue: CORE-16458
Although this PR doesn't fix that shutdown issue, it at least improves the situation with replaced system files and allows to investigate it more.
## Proposed changes
- Add a stub for the function in `dll/win32/rpcrt4/rpc_async.c`;
- Properly call it in `dll/win32/rpcrt4/rpcrt4.spec`.
There is no need to compile our DLLs as shared libraries since we are
managing symbols exports and imports through spec files.
On my system, this reduces the configure-time by a factor of two.
