[JS IR] IC improvements

- Reuse a built fragment
  - Use cache for saving built JS code

js/js.translator/testData/incremental/invalidation/moveFilesBetweenModules/lib1/module.info

@@ -5,8 +5,6 @@ STEP 1:
     dependencies: stdlib
     modifications:
         D : l12.kt
-    dirty:
-
 STEP 2:
     dependencies: stdlib
     modifications:

js/js.translator/testData/incremental/invalidation/moveFilesBetweenModules/lib2/module.info

@@ -1,15 +1,13 @@
 STEP 0:
     dependencies: stdlib, lib1
     dirty: l21.kt
-
 STEP 1:
     dependencies: stdlib, lib1
     modifications:
         U : l22.kt.1 -> l22.kt
     dirty: l21.kt, l22.kt
-
 STEP 2:
     dependencies: stdlib, lib1
     modifications:
         D : l22.kt
-    dirty: l21.kt
+    dirty: l21.kt

js/js.translator/testData/incremental/invalidation/moveFilesBetweenModules/lib3/module.info

@@ -1,11 +1,3 @@
-STEP 0:
+STEP 0..2:
     dependencies: stdlib, lib1, lib2
     dirty: l3.kt
-
-STEP 1:
-    dependencies: stdlib, lib1, lib2
-    dirty: l3.kt
-
-STEP 2:
-    dependencies: stdlib, lib1, lib2
-    dirty: l3.kt

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

@@ -1,2 +1,10 @@
 
-fun box() = dex(4, 2)
+fun box(stepId: Int): String {
+    when (stepId) {
+        0 -> if (dex(4, 2) != 11) return "Fail"
+        1 -> if (dex(4, 2) != 10) return "Fail"
+        2 -> if (dex(4, 2) != 9) return "Fail"
+        else -> return "Unknown"
+    }
+    return "OK"
+}

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

@@ -1,11 +1,3 @@
-STEP 0:
+STEP 0..2:
     dependencies: stdlib, lib1, lib2, lib3
     dirty: m.kt
-
-STEP 1:
-    dependencies: stdlib, lib1, lib2, lib3
-    dirty: m.kt
-
-STEP 2:
-    dependencies: stdlib, lib1, lib2, lib3
-    dirty: m.kt

js/js.translator/testData/incremental/invalidation/moveFilesBetweenModules/project.info

@@ -2,9 +2,7 @@ MODULES: lib1, lib2, lib3, main
 
 STEP 0:
     libs: lib1, lib2, lib3, main
-
-STEP 1:
+    dirty js: stdlib, lib1, lib2, lib3, main
+STEP 1..2:
     libs: lib1, lib2, lib3, main
-
-STEP 2:
-    libs: lib1, lib2, lib3, main
+    dirty js: lib1, lib2, lib3, main