FIR: don't report EQUALITY_NOT_APPLICABLE for classes from java.*

Workaround for KT-48113

compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/IntersectionWithJavaString.fir.txt

@@ -0,0 +1,9 @@
+FILE: IntersectionWithJavaString.kt
+    public final fun collapse(path: R|kotlin/String|): R|kotlin/Unit| {
+        lval result: R|ft<kotlin/String, kotlin/String?>| = (R|<local>/path| as R|java/lang/String|).R|java/lang/String.replace|(String(123), String(456))
+        when () {
+            !==(R|<local>/result|, R|<local>/path|) ->  {
+            }
+        }
+
+    }

compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/IntersectionWithJavaString.kt

@@ -0,0 +1,5 @@
+// FULL_JDK
+fun collapse(path: String) {
+    val result = (path as java.lang.String).replace("123", "456")
+    if (<!EQUALITY_NOT_APPLICABLE_WARNING!>result !== path<!>) {}
+}

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticTestGenerated.java

@@ -5045,6 +5045,12 @@ public class FirDiagnosticTestGenerated extends AbstractFirDiagnosticTest {
                 runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/EnumWithToString.kt");
             }
 
+            @Test
+            @TestMetadata("IntersectionWithJavaString.kt")
+            public void testIntersectionWithJavaString() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/IntersectionWithJavaString.kt");
+            }
+
             @Test
             @TestMetadata("UastPatterns.kt")
             public void testUastPatterns() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticsWithLightTreeTestGenerated.java

@@ -5045,6 +5045,12 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
                 runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/EnumWithToString.kt");
             }
 
+            @Test
+            @TestMetadata("IntersectionWithJavaString.kt")
+            public void testIntersectionWithJavaString() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/IntersectionWithJavaString.kt");
+            }
+
             @Test
             @TestMetadata("UastPatterns.kt")
             public void testUastPatterns() throws Exception {

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/ConeTypeCompatibilityChecker.kt

@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.fir.symbols.ConeClassLikeLookupTag
 import org.jetbrains.kotlin.fir.symbols.ConeTypeParameterLookupTag
 import org.jetbrains.kotlin.fir.symbols.impl.*
 import org.jetbrains.kotlin.fir.types.*
+import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.name.StandardClassIds
 import org.jetbrains.kotlin.types.Variance
 
@@ -212,10 +213,10 @@ internal object ConeTypeCompatibilityChecker {
         val classes = classesOrInterfaces.filter { !it.isInterface }
         // Java force single inheritance, so any pair of unrelated classes are incompatible.
         if (classes.size >= 2) {
-            return if (classes.any { it.getHasPredefinedEqualityContract(this) }) {
+            return when {
-                compatibilityUpperBound
+                classes.any { it.firClass.classId.packageFqName.startsWith(Name.identifier("java")) } -> Compatibility.SOFT_INCOMPATIBLE
-            } else {
+                classes.any { it.getHasPredefinedEqualityContract(this) } -> compatibilityUpperBound
-                Compatibility.SOFT_INCOMPATIBLE
+                else -> Compatibility.SOFT_INCOMPATIBLE
             }
         }
         val finalClass = classes.firstOrNull { it.isFinal } ?: return null

idea/idea-frontend-fir/idea-fir-low-level-api/tests/org/jetbrains/kotlin/idea/fir/low/level/api/diagnostic/compiler/based/DiagnosisCompilerFirTestdataTestGenerated.java

@@ -5045,6 +5045,12 @@ public class DiagnosisCompilerFirTestdataTestGenerated extends AbstractDiagnosis
                 runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/EnumWithToString.kt");
             }
 
+            @Test
+            @TestMetadata("IntersectionWithJavaString.kt")
+            public void testIntersectionWithJavaString() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolveWithStdlib/intellij/IntersectionWithJavaString.kt");
+            }
+
             @Test
             @TestMetadata("UastPatterns.kt")
             public void testUastPatterns() throws Exception {