8325189: Enable this-escape javac warning in java.base

Reviewed-by: alanb, erikj, naoto, smarks, ihse, joehw, lancea, weijun

src/java.base/share/classes/java/lang/BootstrapMethodError.java

@@ -77,6 +77,7 @@ public class BootstrapMethodError extends LinkageError {
      *
      * @param cause the cause, may be {@code null}.
      */
+    @SuppressWarnings("this-escape")
     public BootstrapMethodError(Throwable cause) {
         // cf. Throwable(Throwable cause) constructor.
         super(cause == null ? null : cause.toString());