Reflect Kotlin's declaration-site variance in Java signatures

compiler/testData/writeSignature/declarationSiteVariance/OutOfInInInPosition.kt

@@ -0,0 +1,10 @@
+class In<in T>
+class Out<out T>
+class X
+
+fun f(p: Out<In<X>>) {}
+
+// method: namespace::f
+// jvm signature:     (LOut;)V
+// generic signature: (LOut<+LIn<-LX;>;>;)V
+// kotlin signature:  (LOut<LIn<LX;>;>;)V