Module usage

Introduces Usages, which is responsible for computing variables usage in semantic blocks
of a function.

Structs

Usage

Usages of variables and member paths in semantic code.

Usages

Usages of member paths in expressions of interest, currently loops and closures.

Enums

MemberPath

Member path (e.g. a.b.c). Unlike ExprVarMemberPath, this is not an expression, and has no syntax pointers.