Tests: copy diagnostic test to codegen/box

This is basically a copy of the test
`diagnostics/tests/j+k/primitiveOverrides/triangleWithFlexibleTypeAndSubstitution4.kt`.
The diagnostic version of the test is not removed because it has
frontend-specific diagnostics `FIR_DUMP` and `SCOPE_DUMP`.

This test is copied to make it clear that it actually passes in K1, and
new errors in K2 here are technically a breaking change, see KT-66529.
The error CONFLICTING_INHERITED_JVM_DECLARATIONS was present there only
because diagnostic tests used parts of the old JVM backend to report JVM
backend diagnostics.

 #KT-66529

compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -28414,6 +28414,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
       runTest("compiler/testData/codegen/box/javaInterop/syntheticPropOverriddenGetter.kt");
     }
 
+    @TestMetadata("triangleWithFlexibleTypeAndSubstitution4.kt")
+    public void testTriangleWithFlexibleTypeAndSubstitution4() {
+      runTest("compiler/testData/codegen/box/javaInterop/triangleWithFlexibleTypeAndSubstitution4.kt");
+    }
+
     @TestMetadata("unresolvedJavaClassInDifferentFile.kt")
     public void testUnresolvedJavaClassInDifferentFile() {
       runTest("compiler/testData/codegen/box/javaInterop/unresolvedJavaClassInDifferentFile.kt");