FIR IDE: Add KtCallableSymbol abstraction

- It should incapsulate callable symbols like functions, properties
and constructors

Co-authored-by: Ilya Kirillov <ilya.kirillov@jetbrains.com>

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/scopes/KtScope.kt

@@ -16,7 +16,7 @@ interface KtScope : ValidityOwner {
 
 
     fun getAllSymbols(): Sequence<KtSymbol>
-    fun getCallableSymbols(): Sequence<KtSymbol>
+    fun getCallableSymbols(): Sequence<KtCallableSymbol>
     fun getClassClassLikeSymbols(): Sequence<KtClassLikeSymbol>
 
     fun containsName(name: Name): Boolean

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/KtCallableSymbol.kt

@@ -0,0 +1,8 @@
+/*
+ * 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.idea.frontend.api.symbols
+
+abstract class KtCallableSymbol : KtSymbol

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/KtFunctionLikeSymbol.kt

@@ -7,7 +7,7 @@ package org.jetbrains.kotlin.idea.frontend.api.symbols
 
 import org.jetbrains.kotlin.name.FqName
 
-sealed class KtFunctionLikeSymbol : KtTypedSymbol, KtSymbolWithKind {
+sealed class KtFunctionLikeSymbol : KtCallableSymbol(), KtTypedSymbol, KtSymbolWithKind {
     abstract val valueParameters: List<KtParameterSymbol>
 }
 

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/KtVariableLikeSymbol.kt

@@ -7,7 +7,7 @@ package org.jetbrains.kotlin.idea.frontend.api.symbols
 
 import org.jetbrains.kotlin.name.FqName
 
-abstract class KtVariableLikeSymbol : KtTypedSymbol, KtNamedSymbol, KtSymbolWithKind
+abstract class KtVariableLikeSymbol : KtCallableSymbol(), KtTypedSymbol, KtNamedSymbol, KtSymbolWithKind
 
 abstract class KtEnumEntrySymbol : KtVariableLikeSymbol() {
     final override val symbolKind: KtSymbolKind get() = KtSymbolKind.MEMBER

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/symbols/markers.kt

@@ -29,6 +29,9 @@ interface KtPossibleExtensionSymbol {
     val receiverType: KtType?
 }
 
+val KtCallableSymbol.isExtension: Boolean
+    get() = (this as? KtPossibleExtensionSymbol)?.isExtension == true
+
 interface KtSymbolWithTypeParameters {
     val typeParameters: List<KtTypeParameterSymbol>
 }