[FIR] Approximate all integer literals which resolved in independent mode

#KT-42016

compiler/testData/ir/irText/stubs/simple.fir.txt

@@ -1,12 +0,0 @@
-FILE fqName:<root> fileName:/simple.kt
-  PROPERTY name:test visibility:public modality:FINAL [val]
-    FIELD PROPERTY_BACKING_FIELD name:test type:kotlin.Int visibility:private [final,static]
-      EXPRESSION_BODY
-        CALL 'public final fun plus (other: kotlin.Int): kotlin.Int [operator] declared in kotlin.Int' type=kotlin.Int origin=null
-          $this: CONST Int type=kotlin.Int value=2
-          other: CONST Int type=kotlin.Int value=2
-    FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test> visibility:public modality:FINAL <> () returnType:kotlin.Int
-      correspondingProperty: PROPERTY name:test visibility:public modality:FINAL [val]
-      BLOCK_BODY
-        RETURN type=kotlin.Nothing from='public final fun <get-test> (): kotlin.Int declared in <root>'
-          GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:test type:kotlin.Int visibility:private [final,static]' type=kotlin.Int origin=null

compiler/testData/ir/irText/stubs/simple.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !DUMP_DEPENDENCIES
 
 val test = 2 + 2