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/coroutines/javaInterop/objectWithSeveralSuspends.kt

@@ -30,10 +30,6 @@ inline fun inlineMe(crossinline c: suspend () -> Unit) = object : SuspendRunnabl
         StateMachineChecker.suspendHere()
         StateMachineChecker.suspendHere()
     }
-    // TODO: call it from run1
-    inline suspend fun inlineMeCapturing() {
-        c(); c()
-    }
 }
 
 inline fun inlineMe2(crossinline c: suspend () -> Unit) = inlineMe { c(); c() }

compiler/testData/codegen/box/syntheticAccessors/kt48331.kt

@@ -0,0 +1,25 @@
+// TARGET_BACKEND: JVM
+// FILE: foo.kt
+package foo
+
+abstract class Base {
+    protected abstract fun foo(): String
+}
+
+// FILE: bar.kt
+import foo.*
+
+abstract class C : Base() {
+    class A : C() {
+        override fun foo() = "OK"
+    }
+
+    class B(val x: C) : C() {
+        // Needs an accessor (`foo` is in another package and `x` is not assignable to `B`)
+        override fun foo() = x.foo()
+
+        fun bar() = foo()
+    }
+}
+
+fun box() = C.B(C.A()).bar()

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()

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

@@ -0,0 +1,11 @@
+// TARGET_BACKEND: JVM
+open class C {
+    protected open fun foo() = "OK"
+}
+
+class D : C() {
+    // same package, but `super` needs to be related by class hierarchy:
+    fun bar() = { super.foo() }
+}
+
+fun box() = D().bar()()