[FIR2IR] Introduce additional built-in symbols prepared in advance

This commit allow to avoid possible conflicts between descriptor-based
and signature-based symbols,
because BE sometimes (e.g. in DeclarationStubGenerator)
creates descriptor-based symbol without checking signature-based

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrConverter.kt

@@ -5,7 +5,6 @@
 
 package org.jetbrains.kotlin.fir.backend
 
-import org.jetbrains.kotlin.backend.common.ir.BuiltinSymbolsBase
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.backend.generators.AnnotationGenerator
@@ -16,6 +15,7 @@ import org.jetbrains.kotlin.fir.descriptors.FirModuleDescriptor
 import org.jetbrains.kotlin.fir.psi
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
 import org.jetbrains.kotlin.fir.signaturer.FirMangler
+import org.jetbrains.kotlin.fir.symbols.FirBuiltinSymbols
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrFileImpl
 import org.jetbrains.kotlin.ir.declarations.impl.IrModuleFragmentImpl
@@ -185,7 +185,7 @@ class Fir2IrConverter(
             constantValueGenerator.typeTranslator = typeTranslator
             typeTranslator.constantValueGenerator = constantValueGenerator
             val builtIns = IrBuiltIns(moduleDescriptor.builtIns, typeTranslator, symbolTable)
-            BuiltinSymbolsBase(builtIns, moduleDescriptor.builtIns, symbolTable)
+            FirBuiltinSymbols(builtIns, moduleDescriptor.builtIns, symbolTable)
             val sourceManager = PsiSourceManager()
             val components = Fir2IrComponentsStorage(session, scopeSession, symbolTable, builtIns, mangler)
             val conversionScope = Fir2IrConversionScope()

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/symbols/FirBuiltinSymbols.kt

@@ -0,0 +1,35 @@
+/*
+ * 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.fir.symbols
+
+import org.jetbrains.kotlin.backend.common.ir.BuiltinSymbolsBase
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.incremental.components.NoLookupLocation
+import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
+import org.jetbrains.kotlin.ir.util.ReferenceSymbolTable
+import org.jetbrains.kotlin.name.Name
+
+class FirBuiltinSymbols(
+    irBuiltIns: IrBuiltIns,
+    builtIns: KotlinBuiltIns,
+    symbolTable: ReferenceSymbolTable
+) : BuiltinSymbolsBase(irBuiltIns, builtIns, symbolTable) {
+
+    init {
+        val builtInsPackage = builtInsPackage("kotlin")
+        // Comparable is a base interface for many pre-generated built-in classes,
+        // like String, so it's easier if it's generated together with them
+        // Otherwise we have problems like "IrLazyClass inherits Fir2IrLazyClass",
+        // which does not work properly yet
+        for (name in listOf("Comparable")) {
+            (builtInsPackage.getContributedClassifier(
+                Name.identifier(name),
+                NoLookupLocation.FROM_BACKEND
+            ) as? ClassDescriptor)?.let { symbolTable.referenceClass(it) }
+        }
+    }
+}