FIR IDE: allow getting overridden symbols on any callable symbols

This way caller don't need to first check if the symbol is allowed to
override. The current API throws for cases like Java field, or enum
entry, which is not very user-friendly.

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirSymbolDeclarationOverridesProvider.kt

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.analysis.api.fir.components
 import org.jetbrains.kotlin.fir.analysis.checkers.toRegularClassSymbol
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.utils.superConeTypes
+import org.jetbrains.kotlin.fir.java.declarations.FirJavaField
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
 import org.jetbrains.kotlin.fir.scopes.*
 import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
@@ -57,7 +58,7 @@ internal class KtFirSymbolDeclarationOverridesProvider(
     private fun FirTypeScope.processCallableByName(declaration: FirDeclaration) = when (declaration) {
         is FirSimpleFunction -> processFunctionsByName(declaration.name) { }
         is FirProperty -> processPropertiesByName(declaration.name) { }
-        else -> error { "Invalid FIR symbol to process: ${declaration::class}" }
+        else -> Unit
     }
 
     private fun FirTypeScope.processAllOverriddenDeclarations(
@@ -72,7 +73,7 @@ internal class KtFirSymbolDeclarationOverridesProvider(
             processor.invoke(symbol.fir)
             ProcessorAction.NEXT
         }
-        else -> error { "Invalid FIR symbol to process: ${declaration::class}" }
+        else -> ProcessorAction.STOP
     }
 
     private fun FirTypeScope.processDirectOverriddenDeclarations(
@@ -87,7 +88,7 @@ internal class KtFirSymbolDeclarationOverridesProvider(
             processor.invoke(symbol.fir)
             ProcessorAction.NEXT
         }
-        else -> error { "Invalid FIR symbol to process: ${declaration::class}" }
+        else -> ProcessorAction.STOP
     }
 
     private inline fun <T : KtSymbol> processOverrides(

analysis/analysis-api-fir/tests/org/jetbrains/kotlin/analysis/api/fir/components/OverriddenDeclarationProviderTestGenerated.java

@@ -66,6 +66,12 @@ public class OverriddenDeclarationProviderTestGenerated extends AbstractOverridd
         runTest("analysis/analysis-api/testData/components/overridenDeclarations/multipleInterfaces.kt");
     }
 
+    @Test
+    @TestMetadata("onEnumEntry.kt")
+    public void testOnEnumEntry() throws Exception {
+        runTest("analysis/analysis-api/testData/components/overridenDeclarations/onEnumEntry.kt");
+    }
+
     @Test
     @TestMetadata("sequenceOfOverrides.kt")
     public void testSequenceOfOverrides() throws Exception {

analysis/analysis-api/testData/components/overridenDeclarations/onEnumEntry.kt

@@ -0,0 +1,3 @@
+enum class MyEnum {
+    My<caret>Entry
+}

analysis/analysis-api/testData/components/overridenDeclarations/onEnumEntry.txt

@@ -0,0 +1,2 @@
+ALL:
+DIRECT: