Fix Class.getConstructor("whatever", (Class[]) null).

The RI treats null parameterTypes the same as an empty array.
This behavior is specified for getMethod, but only implied for getConstructor.

This patch:

* Fixes getConstructor.
* Improves javadoc for Class methods taking "Class... parameterTypes".
* Adds tests for both getConstructor and getMethod (which was already correct).
* Removes a line of debugging output to System.out.

Bug: 1824973
3 files changed