Use -opt-in instead of -Xopt-in in comments and scripts

libraries/stdlib/common/build.gradle

@@ -40,9 +40,9 @@ compileKotlinCommon {
     kotlinOptions {
         freeCompilerArgs = [
                 "-module-name", project.name,
-                "-Xopt-in=kotlin.RequiresOptIn",
-                "-Xopt-in=kotlin.ExperimentalMultiplatform",
-                "-Xopt-in=kotlin.contracts.ExperimentalContracts",
+                "-opt-in=kotlin.RequiresOptIn",
+                "-opt-in=kotlin.ExperimentalMultiplatform",
+                "-opt-in=kotlin.contracts.ExperimentalContracts",
                 "-Xallow-kotlin-package",
         ]
     }
@@ -51,9 +51,9 @@ compileKotlinCommon {
 compileTestKotlinCommon {
     kotlinOptions {
         freeCompilerArgs += [
-                "-Xopt-in=kotlin.RequiresOptIn",
-                "-Xopt-in=kotlin.ExperimentalUnsignedTypes",
-                "-Xopt-in=kotlin.ExperimentalStdlibApi",
+                "-opt-in=kotlin.RequiresOptIn",
+                "-opt-in=kotlin.ExperimentalUnsignedTypes",
+                "-opt-in=kotlin.ExperimentalStdlibApi",
         ]
     }
 }

libraries/stdlib/common/src/kotlin/JsAnnotationsH.kt

@@ -21,7 +21,7 @@ public expect annotation class JsName(val name: String)
  *
  * Usages of such annotations will be reported as warnings unless an explicit opt-in with
  * the [OptIn] annotation, e.g. `@OptIn(ExperimentalJsExport::class)`,
- * or with the `-Xopt-in=kotlin.js.ExperimentalJsExport` compiler option is given.
+ * or with the `-opt-in=kotlin.js.ExperimentalJsExport` compiler option is given.
  */
 @Suppress("DEPRECATION")
 @Experimental(level = Experimental.Level.WARNING)