FIR: Use flexible type for generic parameters bounds

Otherwise star projections may be incorrectly approximated to strictly
nullable types (as in test)

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/JavaSymbolProvider.kt

@@ -92,7 +92,7 @@ class JavaSymbolProvider(
         stack: JavaTypeParameterStack,
     ) {
         for (upperBound in javaTypeParameter.upperBounds) {
-            bounds += upperBound.toFirResolvedTypeRef(this@JavaSymbolProvider.session, stack, nullability = ConeNullability.NULLABLE)
+            bounds += upperBound.toFirResolvedTypeRef(this@JavaSymbolProvider.session, stack, nullability = ConeNullability.UNKNOWN)
         }
         addDefaultBoundIfNecessary()
     }

compiler/fir/resolve/testData/resolve/inference/capturedTypeForJavaTypeParameter.kt

@@ -0,0 +1,11 @@
+// FILE: B.java
+public class B<E extends A> {}
+
+// FILE: main.kt
+interface A {}
+
+fun <D : A> foo(b: B<D>) {}
+
+fun main(b: B<*>) {
+    foo(b)
+}

compiler/fir/resolve/testData/resolve/inference/capturedTypeForJavaTypeParameter.txt

@@ -0,0 +1,8 @@
+FILE: main.kt
+    public abstract interface A : R|kotlin/Any| {
+    }
+    public final fun <D : R|A|> foo(b: R|B<D>|): R|kotlin/Unit| {
+    }
+    public final fun main(b: R|B<*>|): R|kotlin/Unit| {
+        R|/foo|<R|captured type: lowerType = null|>(R|<local>/b|)
+    }

compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirDiagnosticsTestGenerated.java

@@ -924,6 +924,11 @@ public class FirDiagnosticsTestGenerated extends AbstractFirDiagnosticsTest {
             runTest("compiler/fir/resolve/testData/resolve/inference/callableReferenceOnInstance.kt");
         }
 
+        @TestMetadata("capturedTypeForJavaTypeParameter.kt")
+        public void testCapturedTypeForJavaTypeParameter() throws Exception {
+            runTest("compiler/fir/resolve/testData/resolve/inference/capturedTypeForJavaTypeParameter.kt");
+        }
+
         @TestMetadata("nestedLambdas.kt")
         public void testNestedLambdas() throws Exception {
             runTest("compiler/fir/resolve/testData/resolve/inference/nestedLambdas.kt");

compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirDiagnosticsWithLightTreeTestGenerated.java

@@ -924,6 +924,11 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
             runTest("compiler/fir/resolve/testData/resolve/inference/callableReferenceOnInstance.kt");
         }
 
+        @TestMetadata("capturedTypeForJavaTypeParameter.kt")
+        public void testCapturedTypeForJavaTypeParameter() throws Exception {
+            runTest("compiler/fir/resolve/testData/resolve/inference/capturedTypeForJavaTypeParameter.kt");
+        }
+
         @TestMetadata("nestedLambdas.kt")
         public void testNestedLambdas() throws Exception {
             runTest("compiler/fir/resolve/testData/resolve/inference/nestedLambdas.kt");