Always run codegen when IC is enabled

We may need to run code generation when no source files are specified
for incremental compilation (to update caches & metadata)

jps-plugin/jps-tests/test/org/jetbrains/kotlin/jps/build/IncrementalJpsTestGenerated.java

@@ -752,6 +752,11 @@ public class IncrementalJpsTestGenerated extends AbstractIncrementalJpsTest {
             runTest("jps-plugin/testData/incremental/pureKotlin/classRecreated/");
         }
 
+        @TestMetadata("classRemoved")
+        public void testClassRemoved() throws Exception {
+            runTest("jps-plugin/testData/incremental/pureKotlin/classRemoved/");
+        }
+
         @TestMetadata("classSignatureChanged")
         public void testClassSignatureChanged() throws Exception {
             runTest("jps-plugin/testData/incremental/pureKotlin/classSignatureChanged/");