Equality comparison for bound callable references takes into account bound receiver.

Fixed KT-14939: use expected receiver type when generating receiver code in get/set methods for bound property references.
Otherwise we have VerifyError for bound receiver 'null' of type 'Nothing?', which is mapped to 'java.lang.Void'.

TODO: proper equality comparison for property accessors ('x::prop.getter', 'x::prop.setter').

compiler/testData/codegen/box/callableReference/bound/equals/nullableReceiverInEquals.kt

@@ -0,0 +1,37 @@
+// TODO: investigate should it be ran for JS or not
+// IGNORE_BACKEND: JS
+
+// See https://youtrack.jetbrains.com/issue/KT-14938
+// WITH_REFLECT
+
+class A
+
+val a = A()
+val aa = A()
+
+fun A?.foo() {}
+
+var A?.bar: Int
+    get() = 42
+    set(value) {}
+
+val aFoo = a::foo
+val A_foo = A::foo
+val nullFoo = null::foo
+
+val aBar = a::bar
+val A_bar = A::bar
+val nullBar = null::bar
+
+fun box(): String =
+        when {
+            nullFoo != null::foo -> "Bound extension refs with same receiver SHOULD be equal"
+            nullFoo == aFoo -> "Bound extension refs with different receivers SHOULD NOT be equal"
+            nullFoo == A_foo -> "Bound extension ref with receiver 'null' SHOULD NOT be equal to free ref"
+
+            nullBar != null::bar -> "Bound extension property refs with same receiver SHOULD be equal"
+            nullBar == aBar -> "Bound extension property refs with different receivers SHOULD NOT be equal"
+            nullBar == A_bar -> "Bound extension property ref with receiver 'null' SHOULD NOT be equal to free property ref"
+
+            else -> "OK"
+        }

compiler/testData/codegen/box/callableReference/bound/equals/receiverInEquals.kt

@@ -0,0 +1,27 @@
+// TODO: investigate should it be ran for JS or not
+// IGNORE_BACKEND: JS
+
+package test
+
+class A {
+    fun foo() {}
+    fun bar() {}
+}
+
+val a = A()
+val aa = A()
+
+val aFoo = a::foo
+val aBar = a::bar
+val aaFoo = aa::foo
+val A_foo = A::foo
+
+fun box(): String =
+        when {
+            aFoo != a::foo -> "Bound refs with same receiver SHOULD be equal"
+            aFoo == aBar -> "Bound refs to different members SHOULD NOT be equal"
+            aFoo == aaFoo -> "Bound refs with different receiver SHOULD NOT be equal"
+            aFoo == A_foo -> "Bound ref SHOULD NOT be equal to free ref"
+
+            else -> "OK"
+        }