[IR] Support user-defined equals for MFVC

Signed-off-by: Evgeniy.Zhelenskiy <Evgeniy.Zhelenskiy@jetbrains.com>

#KT-1179

compiler/testData/codegen/box/valueClasses/mfvcHashCodeOverride.kt

@@ -0,0 +1,18 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+// https://youtrack.jetbrains.com/issue/KT-52236/Different-modality-in-psi-and-fir
+// WITH_STDLIB
+// WORKS_WHEN_VALUE_CLASS
+// LANGUAGE: +ValueClasses, +CustomEqualsInValueClasses
+// TARGET_BACKEND: JVM_IR
+// CHECK_BYTECODE_LISTING
+
+OPTIONAL_JVM_INLINE_ANNOTATION
+value class A(val value1: MyClass, val value2: MyClass) {
+    override fun hashCode() = 42
+}
+
+class MyClass() {
+    override fun hashCode() = -1
+}
+
+fun box(): String = if (A(MyClass(), MyClass()).hashCode() == 42) "OK" else "Fail"