Correctly importing Optional::get() as -> T causes MethodNotFound #439

We are now able to handle generics more properly in wrap-java and now we import Optional as:

@JavaClass("java.util.Optional")
open class JavaOptional<T: AnyJavaObject>: JavaObject {
  @JavaMethod
  open func get() -> T!

which then crashes

SwiftJava/JavaOptional.swift:2: Fatal error: 'try!' expression unexpectedly raised an error: java.lang.NoSuchMethodError: Ljava/util/Optional;.get()Ljava/lang/String;

so the String bit is coming unexpectedly because Swift sees the reified generic type as "String" and not "some T" therefore the downcall is forming an incorrect signature.

The problem is somewhere in the dynamicJavaMethodCall infra which can't handle the generic properly when forming the downcall signature