Minor, add BuiltInsBinaryVersion.readFrom(InputStream)

core/descriptors/src/org/jetbrains/kotlin/builtins/BuiltInsBinaryVersion.kt

@@ -17,6 +17,8 @@
 package org.jetbrains.kotlin.builtins
 
 import org.jetbrains.kotlin.serialization.deserialization.BinaryVersion
+import java.io.DataInputStream
+import java.io.InputStream
 
 /**
  * The version of the format in which the .kotlin_builtins file is stored. This version also includes the version
@@ -28,5 +30,10 @@ class BuiltInsBinaryVersion(vararg numbers: Int) : BinaryVersion(*numbers) {
     companion object {
         @JvmField
         val INSTANCE = BuiltInsBinaryVersion(1, 0, 0)
+
+        fun readFrom(stream: InputStream): BuiltInsBinaryVersion {
+            val dataInput = DataInputStream(stream)
+            return BuiltInsBinaryVersion(*(1..dataInput.readInt()).map { dataInput.readInt() }.toIntArray())
+        }
     }
 }

core/descriptors/src/org/jetbrains/kotlin/builtins/BuiltinsPackageFragment.kt

@@ -23,7 +23,6 @@ import org.jetbrains.kotlin.serialization.deserialization.DeserializedPackageFra
 import org.jetbrains.kotlin.serialization.deserialization.NameResolverImpl
 import org.jetbrains.kotlin.serialization.deserialization.descriptors.DeserializedPackageMemberScope
 import org.jetbrains.kotlin.storage.StorageManager
-import java.io.DataInputStream
 import java.io.InputStream
 
 class BuiltinsPackageFragment(
@@ -34,8 +33,7 @@ class BuiltinsPackageFragment(
 ) : DeserializedPackageFragment(fqName, storageManager, module, BuiltInsSerializedResourcePaths, loadResource) {
     private val builtinsMessage = run {
         val stream = loadResourceSure(BuiltInsSerializedResourcePaths.getBuiltInsFilePath(fqName))
-        val dataInput = DataInputStream(stream)
+        val version = BuiltInsBinaryVersion.readFrom(stream)
-        val version = BuiltInsBinaryVersion(*(1..dataInput.readInt()).map { dataInput.readInt() }.toIntArray())
 
         if (!version.isCompatible()) {
             // TODO: report a proper diagnostic