Drop a part of compileTimeConstants.kt that is not serializable in K2

Basically `val a = 10; val b = a + 20` will not be serialized for
`b` property because `a` is not constant

native/native.tests/testData/klibContents/builtinsSerializer/compileTimeConstants.kt

@@ -1,5 +1,3 @@
-// MUTED_WHEN: K2
-// `val b = a + 20` will not be serialized in K2
 package test
 
 enum class Weapon {
@@ -20,9 +18,6 @@ val doubleConst: Double = 3.0
 val enumConst: Weapon? = Weapon.ROCK
 val arrayConst: Any = byteArrayOf(1,2)
 
-val a = 10
-val b = a + 20
-
 class Class {
     val byteConst: Byte = 10
     val shortConst: Short = 20
@@ -35,7 +30,4 @@ class Class {
     val doubleConst: Double = 3.0
     val enumConst: Weapon? = Weapon.ROCK
     val arrayConst: Any = byteArrayOf(1,2)
-    val a = 10
-    val b = a + 20
 }
-

native/native.tests/testData/klibContents/builtinsSerializer/compileTimeConstants.txt

@@ -1,7 +1,5 @@
     class Class constructor() {
-        val a: Int = 10
         val arrayConst: Any = {1.toByte(), 2.toByte()}
-        val b: Int = 30
         val booleanConst: Boolean = true
         val byteConst: Byte = 10.toByte()
         val charConst: Char = \u0041 ('A')
@@ -18,9 +16,7 @@
         enum entry PAPER
         enum entry SCISSORS
     }
-    val a: Int = 10
     val arrayConst: Any = {1.toByte(), 2.toByte()}
-    val b: Int = 30
     val booleanConst: Boolean = true
     val byteConst: Byte = 10.toByte()
     val charConst: Char = \u0041 ('A')