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/inlineClassBothEqualsOverride.kt

@@ -0,0 +1,55 @@
+// WITH_STDLIB
+// WORKS_WHEN_VALUE_CLASS
+// LANGUAGE: +ValueClasses, +CustomEqualsInInlineClasses
+// TARGET_BACKEND: JVM_IR
+
+
+interface I {
+    fun getVal(): Int
+}
+
+OPTIONAL_JVM_INLINE_ANNOTATION
+value class IC1(val x: Int) : I {
+    override fun getVal(): Int {
+        return x
+    }
+
+    fun equals(other: IC1): Boolean {
+        return x == other.x
+    }
+
+    override fun equals(other: Any?): Boolean {
+        if (other !is I) {
+            return false
+        }
+        return getVal() == other.getVal()
+    }
+
+    override fun hashCode(): Int {
+        return getVal()
+    }
+}
+
+OPTIONAL_JVM_INLINE_ANNOTATION
+value class IC2(val y: Int) : I {
+    override fun getVal(): Int {
+        return y * 10
+    }
+
+    fun equals(other: IC2): Boolean {
+        return y == other.y
+    }
+
+    override fun equals(other: Any?): Boolean {
+        if (other !is I) {
+            return false
+        }
+        return getVal() == other.getVal()
+    }
+
+    override fun hashCode(): Int {
+        return getVal()
+    }
+}
+
+fun box(): String = if (setOf(IC1(10), IC2(1)).size == 1) "OK" else "Fail"