DML Type System

[JonatanWaern]

Currently the server only tracks the locations of type references, and does not attempt to construct semantic descriptions of types, as a result we cannot currently:

• Got ref/def on types
• Detect assignments of incorrect type, including passing wrong type of argument
• Detect attempts to access non-shared methods from shared contexts
• Detect cyclic types, or conflicting type names
• Detect invalid layout or bitfield definitions
• Detect invalid usage of hook or saved types
• And probably more stuff

[JonatanWaern]

#232 adds basic type-system semantics, together with goto-def and find-ref functionality on type declarations and references. It also adds goto-type-decl support for references, likely only restricted by our current restrictions on reference resolution (limited by #13 ), and override type checks on arguments/returns.