Support of custom 'equals' and 'hashCode' in inline classes

'equals' from any made available for overriding in inline classes
'typed' equals made available for definition in inline classes
'typed' equals definition made compulsory if 'untyped' is overridden
'operator' keyword is allowed in 'typed' equals definition

^KT-24874: Fixed

compiler/testData/codegen/box/inlineClasses/inlineClassEqualsConsistency.kt

@@ -0,0 +1,47 @@
+// WITH_STDLIB
+// WORKS_WHEN_VALUE_CLASS
+// LANGUAGE: +ValueClasses, +CustomEqualsInInlineClasses
+// TARGET_BACKEND: JVM_IR
+
+import java.lang.AssertionError
+import kotlin.math.abs
+
+OPTIONAL_JVM_INLINE_ANNOTATION
+value class IC1(val x: Double) {
+    fun equals(other: IC1): Boolean {
+        return abs(x - other.x) < 0.5
+    }
+}
+
+OPTIONAL_JVM_INLINE_ANNOTATION
+value class IC2(val x: Int) {
+    override fun equals(other: Any?): Boolean {
+        if (other !is IC2) {
+            return false
+        }
+        return abs(x - other.x) < 2
+    }
+}
+
+fun box(): String {
+    val a1Typed: IC1 = IC1(1.0)
+    val b1Typed: IC1 = IC1(1.1)
+    val c1Typed: IC1 = IC1(5.0)
+    val a1Untyped: Any = a1Typed
+    val b1Untyped: Any = b1Typed
+    val c1Untyped: Any = c1Typed
+
+    val a2Typed: IC2 = IC2(1)
+    val b2Typed: IC2 = IC2(2)
+    val c2Typed: IC2 = IC2(5)
+    val a2Untyped: Any = a2Typed
+    val b2Untyped: Any = b2Typed
+    val c2Untyped: Any = c2Typed
+
+    if ((a1Typed == b1Typed) != (a1Untyped == b1Untyped)) throw AssertionError()
+    if ((a1Typed == c1Typed) != (a1Untyped == c1Untyped)) throw AssertionError()
+    if ((a2Typed == b2Typed) != (a2Untyped == b2Untyped)) throw AssertionError()
+    if ((a2Typed == c2Typed) != (a2Untyped == c2Untyped)) throw AssertionError()
+
+    return "OK"
+}