Added diagnostic tests for inference and incorporation

compiler/testData/diagnostics/tests/inference/commonSystem/kt3372toCollection.kt

@@ -0,0 +1,12 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+// !CHECK_TYPE
+// KT-3372 Use upper bound in type argument inference
+
+import java.util.HashSet
+
+fun <T, C: MutableCollection<T>> Iterable<T>.toCollection(result: C) : C = throw Exception()
+
+fun test(list: List<Int>) {
+    val set = list.toCollection(HashSet())
+    set checkType { _<HashSet<Int>>() }
+}