[JS IR] Ignore unbound symbols in IC infrastructure

The IR linker is responsible for detecting unbound symbols,
 if it skips them for some reason, IC infrastructure must not fail
 with unbound symbols exceptions. Anyway, the IR validator
 verifies later if there are unbound symbols in
 reachable IR and generates the corresponding error.

^KT-56602 Fixed

js/js.translator/testData/incremental/invalidation/breakKlibBinaryCompatibilityWithVariance/main/m.kt

@@ -0,0 +1,16 @@
+fun box(stepId: Int): String {
+    var x = -1
+    TestClass().test {
+        object : GenericInterface<Int> {
+            init {
+                x = stepId
+            }
+        }
+    }
+
+    when (stepId) {
+        in 0..1 -> if (x != stepId) return "Fail, got $x"
+        else -> return "Unknown"
+    }
+    return "OK"
+}

js/js.translator/testData/incremental/invalidation/breakKlibBinaryCompatibilityWithVariance/main/module.info

@@ -0,0 +1,6 @@
+STEP 0:
+    dependencies: lib1, lib2
+    added file: m.kt
+STEP 1:
+    dependencies: lib1, lib2
+    updated imports: m.kt