New IC: Detect changes to class annotations

Both the new and old incremental compilation (IC) analysis rely on
Kotlin class metadata to detect a change.

However, Kotlin metadata currently doesn't contain info about
annotations (KT-57919), so the IC will not be able to detect a change
to them.

With this commit, we'll fix the new IC such that it can detect a change
to class annotations by not relying only on metadata.

We currently scope this fix to the new IC (cross-module analysis) first.
We'll fix this issue for within-module analysis later.

Performance: There seems to be no performance impact from this change.
Snapshotting the 400MB ideaIC-2022.1.4/app.jar takes 4.1s before and
after this change.

Test: Added ClasspathChangesComputerTest.testChangedAnnotations
^KT-58289: Fixed

compiler/incremental-compilation-impl/test/org/jetbrains/kotlin/incremental/classpathDiff/ClasspathChangesComputerTest.kt

@@ -259,6 +259,9 @@ class KotlinOnlyClasspathChangesComputerTest : ClasspathChangesComputerTest() {
     /** Regression test for KT-55021. */
     @Test
     fun testRenameFileFacade() {
+        // Check that classpath changes computation doesn't fail.
+        // Ideally, the returned changes should be empty (renaming a file facade alone shouldn't cause any `LookupSymbol`s to change), but
+        // it is currently not the case. However, this is just a small efficiency, not a serious bug.
         val changes = computeClasspathChanges(File(testDataDir, "KotlinOnly/testRenameFileFacade/src"), tmpDir)
         Changes(
             lookupSymbols = setOf(
@@ -269,6 +272,20 @@ class KotlinOnlyClasspathChangesComputerTest : ClasspathChangesComputerTest() {
         ).assertEquals(changes)
     }
 
+    /** Regression test for KT-58289.*/
+    @Test
+    fun testChangedAnnotations() {
+        val changes = computeClasspathChanges(File(testDataDir, "KotlinOnly/testChangedAnnotations/src"), tmpDir)
+        Changes(
+            lookupSymbols = setOf(
+                LookupSymbol(name = "SomeClassWithChangedAnnotation", scope = "com.example"),
+            ),
+            fqNames = setOf(
+                "com.example.SomeClassWithChangedAnnotation",
+            )
+        ).assertEquals(changes)
+    }
+
     /** Tests [SupertypesInheritorsImpact]. */
     @Test
     override fun testImpactComputation_SupertypesInheritors() {