code: function enterFunction() {
              lexicalScopeStack.unshift(new Set());
              context.getScope().variables.filter(variable => variable.name === "arguments").forEach(variable => {
                  variable.references.map(ref => ref.identifier).forEach(identifier => argumentsIdentifiers.add(identifier));
              });
          }
docs: Enters a function. This creates a new lexical identifier scope, so a new Set of arrow functions is pushed onto the stack.
  Also, this marks all `arguments` identifiers so that they can be detected later.
  @returns {void}