Add override attribute for invariants.
Fix incorrect property test.
Support auto declarations with selectors.
Add objc files to Xcode project.
Replace 0 with Loc().
Fix invariants after merge.
Fix duplicated error message.
Add workaround for Dwarf exception handling.
First step of adding 64bit support.

This includes using the vtable optimization.
Add support for instance variables.
Disable vtable dispatch for Objective-C methods.
Properly output metadata for classes.
Properly output string literals.
Properly output protocols.
Add missing override.
Fix linker error in the tests.
Compile Objective-C code both for 32 and 64bit.
Output properties.
Fix protocols for 32bit.
Fix test runner.