JVM_IR: try to fix SyntheticAccessorLowering.isAccessible again

The condition on the relationship between the current class and the type
of the receiver for protected members was the opposite of what the JVMS
says, and yet somehow mostly worked?

 #KT-48331 Fixed
 #KT-20542 Fixed

compiler/testData/codegen/box/syntheticAccessors/packagePrivate.kt

@@ -0,0 +1,16 @@
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND: JVM
+// FILE: x.kt
+package x
+
+internal class C {
+    // `foo$default` generated as package-private (not protected):
+    private fun foo(result: String = "OK") = result
+    // this needs an accessor:
+    internal inline fun bar() = foo()
+}
+
+// FILE: y.kt
+import x.*
+
+fun box() = C().bar()