Align externalId

externalId for any field in stubElementTypeHolder has to be prefix (`kotlin`) + dot (`.`) + field name

#KT-53781

compiler/psi/src/org/jetbrains/kotlin/psi/stubs/elements/KtFunctionElementType.java

@@ -34,6 +34,8 @@ import java.io.IOException;
 
 public class KtFunctionElementType extends KtStubElementType<KotlinFunctionStub, KtNamedFunction> {
 
+    private static final String NAME = "kotlin.FUNCTION";
+
     public KtFunctionElementType(@NotNull @NonNls String debugName) {
         super(debugName, KtNamedFunction.class, KotlinFunctionStub.class);
     }
@@ -93,4 +95,10 @@ public class KtFunctionElementType extends KtStubElementType<KotlinFunctionStub,
     public void indexStub(@NotNull KotlinFunctionStub stub, @NotNull IndexSink sink) {
         StubIndexService.getInstance().indexFunction(stub, sink);
     }
+
+    @NotNull
+    @Override
+    public String getExternalId() {
+        return NAME;
+    }
 }

compiler/psi/src/org/jetbrains/kotlin/psi/stubs/elements/KtStubElementType.java

@@ -69,7 +69,7 @@ public abstract class KtStubElementType<StubT extends StubElement<?>, PsiT exten
     @NotNull
     @Override
     public String getExternalId() {
-        return "kotlin." + toString();
+        return "kotlin." + getDebugName();
     }
 
     @Override