Update to ESLint 9

Author: brettz9

.eslintignore

@@ -0,0 +1,72 @@
+import js from "@eslint/js"
+import neostandard from "neostandard"
+import importPlugin from "eslint-plugin-import"
+
+export default [
+  {
+    ignores: [
+      "**/dist/**",
+      "**/test/**",
+      "**/local/**"
+    ]
+  },
+  js.configs.recommended,
+  ...neostandard(),
+  importPlugin.flatConfigs.recommended,
+  {
+    languageOptions: {
+      globals: {
+        BigInt: false,
+        Packages: false
+      }
+    }
+  },
+  {
+    rules: {
+      "@stylistic/indent": [
+        "error",
+        2,
+        {
+          SwitchCase: 0,
+          VariableDeclarator: 2,
+          CallExpression: {arguments: "off"}
+        }
+      ],
+      "@stylistic/new-parens": "off",
+      "@stylistic/no-mixed-operators": "off",
+      "@stylistic/object-curly-spacing": ["error", "never"],
+      "@stylistic/quotes": ["error", "double"],
+      "@stylistic/semi-spacing": "off",
+      "@stylistic/space-before-function-paren": ["error", "never"],
+      "no-unreachable-loop": "off",
+      "no-empty": "off",
+      curly: "off",
+      eqeqeq: ["error", "always", {null: "ignore"}],
+      "new-parens": "off",
+      "no-case-declarations": "off",
+      "no-cond-assign": "off",
+      "no-console": ["error", {allow: ["warn", "error"]}],
+      "no-fallthrough": "off",
+      "no-labels": "off",
+      "no-return-assign": "off",
+      "no-unused-labels": "error",
+      "no-var": "error",
+      "object-shorthand": "off",
+      "one-var": "off",
+      "prefer-const": "off"
+    }
+  },
+  {
+    files: [
+      "acorn/src/bin/*.js",
+      "bin/generate-identifier-regex.js",
+      "bin/generate-unicode-script-values.js"
+    ],
+    languageOptions: {
+      ecmaVersion: 2022
+    },
+    rules: {
+      "no-console": "off"
+    }
+  }
+]