FIR: Do not load hashCode/toString/equals methods from Java interface

As it's done in FE 1.0, and there are subtle semantics in the language that depends on it

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/JavaSymbolProvider.kt

@@ -205,6 +205,7 @@ class JavaSymbolProvider(
             val classIsAnnotation = classKind == ClassKind.ANNOTATION_CLASS
 
             for (javaMethod in javaClass.methods) {
+                if (javaMethod.isObjectMethodInInterface()) continue
                 declarations += convertJavaMethodToFir(
                     javaMethod,
                     classId,

compiler/testData/loadJava/compiledJava/sam/Comparator.fir.txt

@@ -1,6 +1,4 @@
 public abstract interface Comparator<T : R|ft<kotlin/Any, kotlin/Any?>!|> : R|kotlin/Any| {
     public abstract fun compare(o1: R|ft<T, T?>!|, o2: R|ft<T, T?>!|): R|kotlin/Int|
 
-    public abstract operator fun equals(obj: R|kotlin/Any?|): R|kotlin/Boolean|
-
 }

compiler/testData/loadJava/compiledJava/sam/InterfaceWithObjectMethod.fir.txt

@@ -1,4 +1,2 @@
 public abstract interface InterfaceWithObjectMethod : R|kotlin/Any| {
-    public abstract fun toString(): R|kotlin/String|
-
 }

core/compiler.common.jvm/src/org/jetbrains/kotlin/load/java/structure/javaLoading.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.load.java.structure
+
+
+fun JavaMember.isObjectMethodInInterface(): Boolean {
+    return containingClass.isInterface && this is JavaMethod && isObjectMethod(this)
+}
+
+private fun isObjectMethod(method: JavaMethod): Boolean {
+    return when (method.name.asString()) {
+        "toString", "hashCode" -> {
+            method.valueParameters.isEmpty()
+        }
+        "equals" -> {
+            isMethodWithOneObjectParameter(method)
+        }
+        else -> false
+    }
+}
+
+private fun isMethodWithOneObjectParameter(method: JavaMethod): Boolean {
+    val parameters = method.valueParameters
+    val type = parameters.singleOrNull()?.type as? JavaClassifierType ?: return false
+    val classifier = type.classifier
+    if (classifier is JavaClass) {
+        val classFqName = classifier.fqName
+        return classFqName != null && classFqName.asString() == "java.lang.Object"
+    }
+    return false
+}

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/components/DescriptorResolverUtils.java

@@ -24,8 +24,6 @@ import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor;
 import org.jetbrains.kotlin.descriptors.ClassConstructorDescriptor;
 import org.jetbrains.kotlin.descriptors.ClassDescriptor;
 import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor;
-import org.jetbrains.kotlin.load.java.structure.*;
-import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.resolve.NonReportingOverrideStrategy;
 import org.jetbrains.kotlin.resolve.OverridingUtil;
@@ -33,7 +31,6 @@ import org.jetbrains.kotlin.serialization.deserialization.ErrorReporter;
 
 import java.util.Collection;
 import java.util.LinkedHashSet;
-import java.util.List;
 import java.util.Set;
 
 public final class DescriptorResolverUtils {
@@ -121,33 +118,4 @@ public final class DescriptorResolverUtils {
         return null;
     }
 
-    public static boolean isObjectMethodInInterface(@NotNull JavaMember member) {
-        return member.getContainingClass().isInterface() && member instanceof JavaMethod && isObjectMethod((JavaMethod) member);
-    }
-
-    private static boolean isObjectMethod(@NotNull JavaMethod method) {
-        String name = method.getName().asString();
-        if (name.equals("toString") || name.equals("hashCode")) {
-            return method.getValueParameters().isEmpty();
-        }
-        else if (name.equals("equals")) {
-            return isMethodWithOneObjectParameter(method);
-        }
-        return false;
-    }
-
-    private static boolean isMethodWithOneObjectParameter(@NotNull JavaMethod method) {
-        List<JavaValueParameter> parameters = method.getValueParameters();
-        if (parameters.size() == 1) {
-            JavaType type = parameters.get(0).getType();
-            if (type instanceof JavaClassifierType) {
-                JavaClassifier classifier = ((JavaClassifierType) type).getClassifier();
-                if (classifier instanceof JavaClass) {
-                    FqName classFqName = ((JavaClass) classifier).getFqName();
-                    return classFqName != null && classFqName.asString().equals("java.lang.Object");
-                }
-            }
-        }
-        return false;
-    }
 }

core/descriptors.jvm/src/org/jetbrains/kotlin/load/java/lazy/descriptors/DeclaredMemberIndex.kt

@@ -16,11 +16,7 @@
 
 package org.jetbrains.kotlin.load.java.lazy.descriptors
 
-import org.jetbrains.kotlin.load.java.components.DescriptorResolverUtils
+import org.jetbrains.kotlin.load.java.structure.*
-import org.jetbrains.kotlin.load.java.structure.JavaClass
-import org.jetbrains.kotlin.load.java.structure.JavaField
-import org.jetbrains.kotlin.load.java.structure.JavaMember
-import org.jetbrains.kotlin.load.java.structure.JavaMethod
 import org.jetbrains.kotlin.name.Name
 
 interface DeclaredMemberIndex {
@@ -44,7 +40,7 @@ open class ClassDeclaredMemberIndex(
     private val memberFilter: (JavaMember) -> Boolean
 ) : DeclaredMemberIndex {
     private val methodFilter = { m: JavaMethod ->
-        memberFilter(m) && !DescriptorResolverUtils.isObjectMethodInInterface(m)
+        memberFilter(m) && !m.isObjectMethodInInterface()
     }
 
     private val methods = jClass.methods.asSequence().filter(methodFilter).groupBy { m -> m.name }