function registerFunction( node ) {
		var name = node.id.name;
		if ( name ) {
			if ( !hasOwnProp( functionHash, name ) ) {
				functionHash[ name ] = {
					'node': node,
					'private': true
				};
			}
		}
	}
Registers a function.

@private
@param {ASTNode} node - node to report