[FIR] Add default upper bound for java type parameters

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

@@ -14,6 +14,7 @@ import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.declarations.FirTypeParameter
 import org.jetbrains.kotlin.fir.declarations.impl.FirTypeParameterImpl
+import org.jetbrains.kotlin.fir.declarations.impl.addDefaultBoundIfNecessary
 import org.jetbrains.kotlin.fir.java.declarations.FirJavaClass
 import org.jetbrains.kotlin.fir.java.declarations.FirJavaConstructor
 import org.jetbrains.kotlin.fir.java.declarations.FirJavaField
@@ -122,6 +123,7 @@ class JavaSymbolProvider(
         for (upperBound in javaTypeParameter.upperBounds) {
             bounds += upperBound.toFirResolvedTypeRef(this@JavaSymbolProvider.session, stack)
         }
+        addDefaultBoundIfNecessary()
     }
 
     private fun List<JavaTypeParameter>.convertTypeParameters(stack: JavaTypeParameterStack): List<FirTypeParameter> {

idea/testData/fir/multiModule/intersectionTypesProblem/extraDump.java.txt

@@ -0,0 +1,12 @@
+public abstract interface Diagnostic : R|kotlin/Any| {
+}
+public abstract interface DiagnosticWithParameters1<E, A> : R|jvm/Diagnostic| {
+    public abstract operator fun getA(): R|ft<A, A?>!|
+
+}
+public abstract interface DiagnosticWithParameters2<E, A, B> : R|jvm/Diagnostic| {
+    public abstract operator fun getA(): R|ft<A, A?>!|
+
+    public abstract operator fun getB(): R|ft<B, B?>!|
+
+}

idea/testData/fir/multiModule/intersectionTypesProblem/jvm/Diagnostic.java

@@ -0,0 +1,3 @@
+package jvm;
+
+public interface Diagnostic {}

idea/testData/fir/multiModule/intersectionTypesProblem/jvm/DiagnosticWithParameters1.java

@@ -0,0 +1,5 @@
+package jvm;
+
+public interface DiagnosticWithParameters1<E, A> extends Diagnostic {
+    A getA();
+}

idea/testData/fir/multiModule/intersectionTypesProblem/jvm/DiagnosticWithParameters2.java

@@ -0,0 +1,6 @@
+package jvm;
+
+public interface DiagnosticWithParameters2<E, A, B> extends Diagnostic {
+    A getA();
+    B getB();
+}

idea/testData/fir/multiModule/intersectionTypesProblem/jvm/test.kt

@@ -0,0 +1,7 @@
+package jvm;
+
+fun <K> select(x: K, y: K): K = x
+
+fun test(d1: DiagnosticWithParameters1<*, *>, d2: DiagnosticWithParameters2<*, *, *>) {
+    val res = select(d1.a, d2.b)
+}

idea/testData/fir/multiModule/intersectionTypesProblem/jvm/test.txt

@@ -0,0 +1,7 @@
+FILE: test.kt
+    public final fun <K> select(x: R|K|, y: R|K|): R|K| {
+        ^select R|<local>/x|
+    }
+    public final fun test(d1: R|jvm/DiagnosticWithParameters1<*, *>|, d2: R|jvm/DiagnosticWithParameters2<*, *, *>|): R|kotlin/Unit| {
+        lval res: R|ft<kotlin/Any?, kotlin/Any?>?| = R|jvm/select|<R|ft<kotlin/Any?, kotlin/Any?>?|>(R|<local>/d1|.R|jvm/DiagnosticWithParameters1.a|, R|<local>/d2|.R|jvm/DiagnosticWithParameters2.b|)
+    }

idea/tests/org/jetbrains/kotlin/idea/fir/FirMultiModuleResolveTestGenerated.java

@@ -64,6 +64,11 @@ public class FirMultiModuleResolveTestGenerated extends AbstractFirMultiModuleRe
         runTest("idea/testData/fir/multiModule/fullWithJavaPredefinedSignature/");
     }
 
+    @TestMetadata("intersectionTypesProblem")
+    public void testIntersectionTypesProblem() throws Exception {
+        runTest("idea/testData/fir/multiModule/intersectionTypesProblem/");
+    }
+
     @TestMetadata("javaGetPrefixConflict")
     public void testJavaGetPrefixConflict() throws Exception {
         runTest("idea/testData/fir/multiModule/javaGetPrefixConflict/");