KT-2752: minor fixes after code review

compiler/backend-common/src/org/jetbrains/kotlin/backend/common/CodegenUtil.kt

@@ -25,11 +25,8 @@ import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.DescriptorUtils
 import org.jetbrains.kotlin.resolve.MemberComparator
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
-import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
 import org.jetbrains.kotlin.types.KotlinType
-import org.jetbrains.kotlin.types.checker.KotlinTypeChecker
 import org.jetbrains.kotlin.types.isDynamic
-import org.jetbrains.kotlin.types.typeUtil.makeNullable
 import org.jetbrains.kotlin.utils.keysToMapExceptNulls
 
 object CodegenUtil {
@@ -153,15 +150,6 @@ object CodegenUtil {
                ?: error("ClassDescriptor of superType should not be null: ${specifier.text}")
     }
 
-    @JvmStatic
-    fun isEnumValueOfMethod(functionDescriptor: FunctionDescriptor): Boolean {
-        val methodTypeParameters = functionDescriptor.valueParameters
-        val nullableString = functionDescriptor.builtIns.stringType.makeNullable()
-        return DescriptorUtils.ENUM_VALUE_OF == functionDescriptor.name
-               && methodTypeParameters.size == 1
-               && KotlinTypeChecker.DEFAULT.isSubtypeOf(methodTypeParameters[0].type, nullableString)
-    }
-
     @JvmStatic
     fun getLineNumberForElement(statement: PsiElement, markEndOffset: Boolean): Int? {
         val file = statement.containingFile

compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java

@@ -820,7 +820,7 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
                 CollectionsKt.single(descriptor.getStaticScope().getContributedFunctions(ENUM_VALUE_OF, NoLookupLocation.FROM_BACKEND), new Function1<FunctionDescriptor, Boolean>() {
                     @Override
                     public Boolean invoke(FunctionDescriptor descriptor) {
-                        return CodegenUtil.isEnumValueOfMethod(descriptor);
+                        return DescriptorUtilsKt.isEnumValueOfMethod(descriptor);
                     }
                 });
         MethodVisitor mv = v.newMethod(JvmDeclarationOriginKt.OtherOrigin(myClass, valueOfFunction), ACC_PUBLIC | ACC_STATIC, ENUM_VALUE_OF.asString(),