[test] Test SRE of a class with two methods with the same name.

[test] Test SRE of a class with two methods with the same name.

Regression test for https://bugzilla.xamarin.com/show_bug.cgi?id=57222

Although methods aren't affected by this bug, I added a regression test for
this case anyway in case the implementation changes.

Currently MethodBuilder.RuntimeResolve() goes through a different codepath - it
calls RuntimeType.GetMethod (MethodInfo) which calls into an icall which looks
for a method with a matching token rather than a matching name.