Build all using clang (needs a patch to COFF).
Change guid_t type to unsigned chars. Rename rest of EFI types.
Add error-check macro.
Remove InitializeLib function stub.
Add constant storage for GUIDs.
Turn SIGNATUREs to constexprs.
Move protocols are basic structures, add more protocols.
Fix guid argument types.
Add public-accessible APIs.
Test protocols requesting.