Fix KotlinReflectionInternalError on encountering 'clone' in a class

`RuntimeTypeMapper.mapSignature` threw exception because the descriptor
for `clone` was created manually in CloneableClassScope and therefore it
didn't have a JVM signature as in deserialized descriptors, and wasn't
recognized as a Java method either.

 #KT-22923 Fixed

compiler/testData/codegen/box/reflection/mapping/methodsFromObject.kt

@@ -30,8 +30,7 @@ fun box(): String {
         MyCustomMembers::class.functions()
     )
 
-    // TODO: KT-22923
+    assertEquals(listOf("clone", "equals", "hashCode", "toString"), MyCloneable::class.functions())
-    // assertEquals(listOf("clone", "equals", "hashCode", "toString"), MyCloneable::class.functions())
 
     return "OK"
 }

core/descriptors.jvm/src/org/jetbrains/kotlin/builtins/jvm/CloneableClassScope.kt

@@ -28,6 +28,6 @@ class CloneableClassScope(
     )
 
     companion object {
-        internal val CLONE_NAME = Name.identifier("clone")
+        val CLONE_NAME = Name.identifier("clone")
     }
 }

core/reflection.jvm/src/kotlin/reflect/jvm/internal/RuntimeTypeMapper.kt

@@ -18,6 +18,7 @@ package kotlin.reflect.jvm.internal
 
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.builtins.PrimitiveType
+import org.jetbrains.kotlin.builtins.jvm.CloneableClassScope
 import org.jetbrains.kotlin.builtins.jvm.JavaToKotlinClassMap
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.load.java.JvmAbi
@@ -199,7 +200,7 @@ internal object RuntimeTypeMapper {
             }
         }
 
-        if (DescriptorFactory.isEnumValueOfMethod(function) || DescriptorFactory.isEnumValuesMethod(function)) {
+        if (isKnownBuiltInFunction(function)) {
             return mapJvmFunctionSignature(function)
         }
 
@@ -235,6 +236,14 @@ internal object RuntimeTypeMapper {
         )
     }
 
+    private fun isKnownBuiltInFunction(descriptor: FunctionDescriptor): Boolean {
+        if (DescriptorFactory.isEnumValueOfMethod(descriptor) || DescriptorFactory.isEnumValuesMethod(descriptor)) return true
+
+        if (descriptor.name == CloneableClassScope.CLONE_NAME && descriptor.valueParameters.isEmpty()) return true
+
+        return false
+    }
+
     private fun mapJvmFunctionSignature(descriptor: FunctionDescriptor): JvmFunctionSignature.KotlinFunction =
         JvmFunctionSignature.KotlinFunction(
             JvmMemberSignature.Method(mapName(descriptor), descriptor.computeJvmDescriptor(withName = false))