Don't report TYPE_INFERENCE_POSTPONED_VARIABLE_IN_RECEIVER_TYPE if unrestricted build inference was enabled

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tower/ResolvedAtomCompleter.kt

@@ -415,7 +415,10 @@ class ResolvedAtomCompleter(
 
         val rawExtensionReceiver = callableCandidate.extensionReceiver
 
-        if (rawExtensionReceiver != null && rawExtensionReceiver.receiver.receiverValue.type.contains { it is StubTypeForBuilderInference }) {
+        val unrestrictedBuilderInferenceSupported =
+            topLevelCallContext.languageVersionSettings.supportsFeature(LanguageFeature.UnrestrictedBuilderInference)
+
+        if (rawExtensionReceiver != null && !unrestrictedBuilderInferenceSupported && rawExtensionReceiver.receiver.receiverValue.type.contains { it is StubTypeForBuilderInference }) {
             topLevelTrace.reportDiagnosticOnce(Errors.TYPE_INFERENCE_POSTPONED_VARIABLE_IN_RECEIVER_TYPE.on(callableReferenceExpression))
             return
         }

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/DoubleColonExpressionResolver.kt

@@ -551,7 +551,9 @@ class DoubleColonExpressionResolver(
                 resolvedCall.extensionReceiver?.type?.contains { it is StubTypeForBuilderInference } == true
             }
 
-        if (doesSomeExtensionReceiverContainsStubType) {
+        val unrestrictedBuilderInferenceSupported = languageVersionSettings.supportsFeature(LanguageFeature.UnrestrictedBuilderInference)
+
+        if (doesSomeExtensionReceiverContainsStubType && !unrestrictedBuilderInferenceSupported) {
             c.trace.reportDiagnosticOnce(TYPE_INFERENCE_POSTPONED_VARIABLE_IN_RECEIVER_TYPE.on(expression))
             return noTypeInfo(c)
         }