Add support for InlineExpectationsTest to Kotlin

Author: atorralba

java/ql/test/TestUtilities/InlineExpectationsTestPrivate.qll

@@ -4,9 +4,19 @@ import java
  * A class representing line comments in Java, which is simply Javadoc restricted
  * to EOL comments, with an extra accessor used by the InlineExpectations core code
  */
-class ExpectationComment extends Javadoc {
-  ExpectationComment() { isEolComment(this) }
-
+abstract class ExpectationComment extends Top {
   /** Gets the contents of the given comment, _without_ the preceding comment marker (`//`). */
-  string getContents() { result = this.getChild(0).toString() }
+  abstract string getContents();
+}
+
+private class JavadocExpectationComment extends Javadoc, ExpectationComment {
+  JavadocExpectationComment() { isEolComment(this) }
+
+  override string getContents() { result = this.getChild(0).toString() }
+}
+
+private class KtExpectationComment extends KtComment, ExpectationComment {
+  override string getContents() {
+    result = this.getText().regexpCapture("(?://|/\\*)(.*)(?:\\*/)?", 1)
+  }
 }