[FIR] Unity FirCallableDeclaration and FirCallableMemberDeclaration

After removal of all diamonds in FirDeclaration hierarchy
  FirCallableMemberDeclaration was only one inheritor of
  FirCallableDeclaration, so there is no need to keep them both

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/api/FirDeclarationDesignation.kt

@@ -58,7 +58,7 @@ private fun collectDesignationPath(declaration: FirDeclaration): List<FirDeclara
     val containingClass = when (declaration) {
         is FirCallableDeclaration -> {
             if (declaration.symbol.callableId.isLocal) return null
-            if ((declaration as? FirCallableMemberDeclaration)?.status?.visibility == Visibilities.Local) return null
+            if ((declaration as? FirCallableDeclaration)?.status?.visibility == Visibilities.Local) return null
             when (declaration) {
                 is FirSimpleFunction, is FirProperty, is FirField, is FirConstructor -> {
                     val klass = declaration.containingClass() ?: return emptyList()

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/renderer/FirIdeRenderer.kt

@@ -115,7 +115,7 @@ internal class FirIdeRenderer private constructor(
             return if (classKind == ClassKind.INTERFACE) Modality.ABSTRACT else Modality.FINAL
         }
         val containingFirClass = containingDeclaration as? FirRegularClass ?: return Modality.FINAL
-        if (this !is FirCallableMemberDeclaration) return Modality.FINAL
+        if (this !is FirCallableDeclaration) return Modality.FINAL
         if (isOverride) {
             if (containingFirClass.modality != Modality.FINAL) return Modality.OPEN
         }
@@ -126,7 +126,7 @@ internal class FirIdeRenderer private constructor(
     }
 
     private fun StringBuilder.renderModalityForCallable(
-        callable: FirCallableMemberDeclaration,
+        callable: FirCallableDeclaration,
         containingDeclaration: FirDeclaration?
     ) {
         val modality = callable.modality ?: return
@@ -137,7 +137,7 @@ internal class FirIdeRenderer private constructor(
         }
     }
 
-    private fun StringBuilder.renderOverride(callableMember: FirCallableMemberDeclaration) {
+    private fun StringBuilder.renderOverride(callableMember: FirCallableDeclaration) {
         if (RendererModifier.OVERRIDE !in options.modifiers) return
         renderModifier(callableMember.isOverride || options.forceRenderingOverrideModifier, "override")
     }

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

@@ -8,7 +8,7 @@ package org.jetbrains.kotlin.idea.frontend.api.fir.symbols
 import org.jetbrains.kotlin.fir.analysis.checkers.getImplementationStatus
 import org.jetbrains.kotlin.fir.analysis.checkers.isVisibleInClass
 import org.jetbrains.kotlin.fir.containingClass
-import org.jetbrains.kotlin.fir.declarations.FirCallableMemberDeclaration
+import org.jetbrains.kotlin.fir.declarations.FirCallableDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirClass
 import org.jetbrains.kotlin.fir.originalForIntersectionOverrideAttr
 import org.jetbrains.kotlin.fir.originalForSubstitutionOverride
@@ -35,7 +35,7 @@ class KtFirOverrideInfoProvider(
         require(memberSymbol is KtFirSymbol<*>)
         require(classSymbol is KtFirSymbol<*>)
         return memberSymbol.firRef.withFir { memberFir ->
-            if (memberFir !is FirCallableMemberDeclaration) return@withFir false
+            if (memberFir !is FirCallableDeclaration) return@withFir false
             classSymbol.firRef.withFir inner@{ parentClassFir ->
                 if (parentClassFir !is FirClass) return@inner false
                 memberFir.isVisibleInClass(parentClassFir)
@@ -47,7 +47,7 @@ class KtFirOverrideInfoProvider(
         require(memberSymbol is KtFirSymbol<*>)
         require(parentClassSymbol is KtFirSymbol<*>)
         return memberSymbol.firRef.withFir { memberFir ->
-            if (memberFir !is FirCallableMemberDeclaration) return@withFir null
+            if (memberFir !is FirCallableDeclaration) return@withFir null
             parentClassSymbol.firRef.withFir inner@{ parentClassFir ->
                 if (parentClassFir !is FirClass) return@inner null
                 memberFir.getImplementationStatus(SessionHolderImpl(firAnalysisSession.rootModuleSession, ScopeSession()), parentClassFir)
@@ -58,7 +58,7 @@ class KtFirOverrideInfoProvider(
     override fun getOriginalContainingClassForOverride(symbol: KtCallableSymbol): KtClassOrObjectSymbol? {
         require(symbol is KtFirSymbol<*>)
         return symbol.firRef.withFir { firDeclaration ->
-            if (firDeclaration !is FirCallableMemberDeclaration) return@withFir null
+            if (firDeclaration !is FirCallableDeclaration) return@withFir null
             with(analysisSession) {
                 getOriginalOverriddenSymbol(firDeclaration)?.containingClass()?.classId?.getCorrespondingToplevelClassOrObjectSymbol()
             }
@@ -68,7 +68,7 @@ class KtFirOverrideInfoProvider(
     override fun getOriginalOverriddenSymbol(symbol: KtCallableSymbol): KtCallableSymbol? {
         require(symbol is KtFirSymbol<*>)
         return symbol.firRef.withFir { firDeclaration ->
-            if (firDeclaration !is FirCallableMemberDeclaration) return@withFir null
+            if (firDeclaration !is FirCallableDeclaration) return@withFir null
             with(analysisSession) {
                 getOriginalOverriddenSymbol(firDeclaration)
                     ?.buildSymbol((analysisSession as KtFirAnalysisSession).firSymbolBuilder) as KtCallableSymbol?
@@ -76,7 +76,7 @@ class KtFirOverrideInfoProvider(
         }
     }
 
-    private fun getOriginalOverriddenSymbol(member: FirCallableMemberDeclaration): FirCallableMemberDeclaration? {
+    private fun getOriginalOverriddenSymbol(member: FirCallableDeclaration): FirCallableDeclaration? {
         val originalForSubstitutionOverride = member.originalForSubstitutionOverride
         if (originalForSubstitutionOverride != null) return getOriginalOverriddenSymbol(originalForSubstitutionOverride)
 

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

@@ -97,7 +97,7 @@ internal fun FirRefWithValidityCheck<FirCallableDeclaration>.receiverTypeAndAnno
     }
 }
 
-internal fun FirRefWithValidityCheck<FirCallableMemberDeclaration>.dispatchReceiverTypeAndAnnotations(builder: KtSymbolByFirBuilder) =
+internal fun FirRefWithValidityCheck<FirCallableDeclaration>.dispatchReceiverTypeAndAnnotations(builder: KtSymbolByFirBuilder) =
     withFir { fir ->
         fir.dispatchReceiverType?.let {
             builder.typeBuilder.buildKtType(it)

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/references/FirReferenceResolveHelper.kt

@@ -73,7 +73,7 @@ internal object FirReferenceResolveHelper {
         val classLikeDeclaration = ConeClassLikeLookupTagImpl(this).toSymbol(session)?.fir
         if (classLikeDeclaration is FirRegularClass) {
             if (calleeReference is FirResolvedNamedReference) {
-                val callee = calleeReference.resolvedSymbol.fir as? FirCallableMemberDeclaration
+                val callee = calleeReference.resolvedSymbol.fir as? FirCallableDeclaration
                 // TODO: check callee owner directly?
                 if (callee !is FirConstructor && callee?.isStatic != true) {
                     classLikeDeclaration.companionObject?.let { return it.buildSymbol(symbolBuilder) }
@@ -98,9 +98,9 @@ internal object FirReferenceResolveHelper {
                             syntheticProperty.setter!!.delegate
                         }
                     }
-                    else -> symbol.fir as? FirDeclaration
+                    else -> symbol.fir
                 }
-                listOfNotNull(fir?.buildSymbol(symbolBuilder))
+                listOfNotNull(fir.buildSymbol(symbolBuilder))
             }
             is FirResolvedCallableReference -> {
                 listOfNotNull(resolvedSymbol.fir.buildSymbol(symbolBuilder))
@@ -112,7 +112,7 @@ internal object FirReferenceResolveHelper {
                 listOfNotNull((superTypeRef as? FirResolvedTypeRef)?.toTargetSymbol(session, symbolBuilder))
             }
             is FirErrorNamedReference -> {
-                getCandidateSymbols().mapNotNull { it.fir.buildSymbol(symbolBuilder) }
+                getCandidateSymbols().map { it.fir.buildSymbol(symbolBuilder) }
             }
             else -> emptyList()
         }
@@ -300,7 +300,7 @@ internal object FirReferenceResolveHelper {
         fir: FirErrorNamedReference,
         symbolBuilder: KtSymbolByFirBuilder
     ): List<KtSymbol> =
-        getFirSymbolsByErrorNamedReference(fir).mapNotNull { it.fir.buildSymbol(symbolBuilder) }
+        getFirSymbolsByErrorNamedReference(fir).map { it.fir.buildSymbol(symbolBuilder) }
 
 
     fun getFirSymbolsByErrorNamedReference(