ast: Improve the compiler detector argument

- case insensitive
- also support "is turbowarp?"

src/compiler/astgen.js

@@ -43,8 +43,9 @@ const createVariableData = (scope, varObj) => ({
 /**
  * Determine whether an input is used as a compiler detector.
  * @param {string} name The name of the argument.
+ * @returns {boolean} true if this argument is a compiler detector, and its value should become `true`
  */
-const isCompilerDetectorArgument = name => name === 'is compiled?';
+const isCompilerDetectorArgument = name => name.toLowerCase() === 'is compiled?' || name.toLowerCase() === 'is turbowarp?';
 
 class ScriptTreeGenerator {
     constructor (thread) {