Unify reserved word checking and update error messages (#9402)

* Unify reserved word checking and update error messages

* Fix test

packages/babel-parser/src/util/identifier.js

@@ -4,27 +4,52 @@
 
 import * as charCodes from "charcodes";
 
-export const isES2015ReservedWord = (word: string): boolean => {
-  return word === "enum" || word === "await";
+const reservedWords = {
+  strict: [
+    "implements",
+    "interface",
+    "let",
+    "package",
+    "private",
+    "protected",
+    "public",
+    "static",
+    "yield",
+  ],
+  strictBind: ["eval", "arguments"],
 };
 
-const reservedWordsStrict = new Set([
-  "implements",
-  "interface",
-  "let",
-  "package",
-  "private",
-  "protected",
-  "public",
-  "static",
-  "yield",
-]);
-export function isStrictReservedWord(word: string): boolean {
-  return reservedWordsStrict.has(word);
+const reservedWordsStrictSet = new Set(reservedWords.strict);
+const reservedWordsStrictBindSet = new Set(
+  reservedWords.strict.concat(reservedWords.strictBind),
+);
+
+/**
+ * Checks if word is a reserved word in non-strict mode
+ */
+export const isReservedWord = (word: string, inModule: boolean): boolean => {
+  return (inModule && word === "await") || word === "enum";
+};
+
+/**
+ * Checks if word is a reserved word in non-binding strict mode
+ *
+ * Includes non-strict reserved words
+ */
+export function isStrictReservedWord(word: string, inModule: boolean): boolean {
+  return isReservedWord(word, inModule) || reservedWordsStrictSet.has(word);
 }
 
-export function isStrictBindReservedWord(word: string): boolean {
-  return word === "eval" || word === "arguments";
+/**
+ * Checks if word is a reserved word in binding strict mode
+ *
+ * Includes non-strict reserved words and non-binding strict reserved words
+ */
+export function isStrictBindReservedWord(
+  word: string,
+  inModule: boolean,
+): boolean {
+  return isReservedWord(word, inModule) || reservedWordsStrictBindSet.has(word);
 }
 
 const keywords = new Set([