Support jvm default methods in IR

Fix several bugs around DefaultImpls

compiler/testData/codegen/box/jvm8/defaults/inheritedFunctionWithDefaultParameters.kt

@@ -0,0 +1,14 @@
+// !JVM_DEFAULT_MODE: enable
+// TARGET_BACKEND: JVM
+// JVM_TARGET: 1.8
+// WITH_RUNTIME
+interface I {
+    @JvmDefault
+    fun foo(x: String = "OK"): String = x
+}
+
+interface J : I
+
+object O : J
+
+fun box(): String = O.foo()