Add enable / disable feature in JPS

#KT-26775 Fixed
#KT-26774 Fixed

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/CliArgumentStringBuilder.kt

@@ -8,7 +8,7 @@ package org.jetbrains.kotlin.cli.common.arguments
 import org.jetbrains.kotlin.config.LanguageFeature
 
 object CliArgumentStringBuilder {
-    const val languagePrefix = "-XXLanguage:"
+    private const val languagePrefix = "-XXLanguage:"
 
     private val LanguageFeature.State.sign: String
         get() = when (this) {
@@ -21,4 +21,30 @@ object CliArgumentStringBuilder {
     fun LanguageFeature.buildArgumentString(state: LanguageFeature.State): String {
         return "$languagePrefix${state.sign}$name"
     }
+
+    fun String.replaceLanguageFeature(
+        feature: LanguageFeature,
+        state: LanguageFeature.State,
+        prefix: String = "",
+        postfix: String = "",
+        separator: String = ", ",
+        quoted: Boolean = true
+    ): String {
+        val existingFeatureIndex = indexOf(feature.name)
+        val languagePrefixIndex = lastIndexOf(languagePrefix, existingFeatureIndex)
+        val featureArgumentString = feature.buildArgumentString(state)
+        val quote = if (quoted) "\"" else ""
+        return if (languagePrefixIndex != -1) {
+            replaceRange(languagePrefixIndex, existingFeatureIndex + feature.name.length, featureArgumentString)
+        } else {
+            val splitText = if (postfix.isNotEmpty()) split(postfix) else listOf(this, "")
+            if (splitText.size != 2) {
+                "$prefix$quote$featureArgumentString$quote$postfix"
+            } else {
+                val (mainPart, commentPart) = splitText
+                // In Groovy / Kotlin DSL, we can have comment after [...] or listOf(...)
+                mainPart + "$separator$quote$featureArgumentString$quote$postfix" + commentPart
+            }
+        }
+    }
 }