Rename AST List types.
Merge branch 'develop' into syntax-v2
Rename astID() -> syntaxID();
add asserts and fix source map emit for classes with memver functions
Syntax elements should store IDs.
Rename script() => sourceUnit();
Update LKG.
Merge branch 'develop' into syntax-v2
Rename astID() -> syntaxID();
Rename script() => sourceUnit();
Update LKG.
Fix code after pull.
Update field name in syntax tree.
Merge branch 'develop' into syntax-v2

Conflicts:
	src/compiler/sourceMapping.ts
Fixing code after merge.
Move method off of SourceUnit.
Merge branch 'develop' into syntax-v2
Provide access to fileName and syntaxTree from syntax elements.
Remove AST almost entirely and no longer translate between syntax nodes and AST nodes.

We're still keeping Comment nodes for now to keep the current emitting behavior.
Emit comments for nodes.