Add internal compiler argument to change metadata version

Will be used in tests to check how we behave on binaries produced by a
"future" compiler

compiler/frontend/src/org/jetbrains/kotlin/config/CommonConfigurationKeys.kt

@@ -18,6 +18,7 @@ package org.jetbrains.kotlin.config
 
 import org.jetbrains.kotlin.incremental.components.ExpectActualTracker
 import org.jetbrains.kotlin.incremental.components.LookupTracker
+import org.jetbrains.kotlin.metadata.deserialization.BinaryVersion
 
 object CommonConfigurationKeys {
     @JvmField
@@ -37,6 +38,9 @@ object CommonConfigurationKeys {
 
     @JvmField
     val EXPECT_ACTUAL_TRACKER = CompilerConfigurationKey.create<ExpectActualTracker>("expect actual tracker")
+
+    @JvmField
+    val METADATA_VERSION = CompilerConfigurationKey.create<BinaryVersion>("metadata version")
 }
 
 var CompilerConfiguration.languageVersionSettings: LanguageVersionSettings