Function internIdentifier

test/fixtures/snapshot/typescript.js:32353–32359

(text)

            return finishNode(result, pos);
        }
        function internIdentifier(text) {
            var identifier = identifiers.get(text);
            if (identifier === undefined) {
                identifiers.set(text, identifier = text);
            }
            return identifier;
        }
        // An identifier that starts with two underscores has an extra underscore character prepended to it to avoid issues
        // with magic property names like '__proto__'. The 'identifiers' object is used to share a single string instance for
        // each identifier in order to reduce memory consumption.