Native: don't add ExperimentalForeignApi to platform libs

Use -Xdisable-experimental-annotation when generating platform libs.
As a result, unlike all other cinterop libraries, declarations in
platform libs won't require ExperimentalForeignApi opt-in

^KT-58362

kotlin-native/platformLibs/build.gradle.kts

@@ -72,7 +72,7 @@ konanTargetList.forEach { target ->
                 libraries {
                     klibs(df.config.depends.map { "${fileNamePrefix}${it}" })
                 }
-                extraOpts("-Xpurge-user-libs", "-Xshort-module-name", df.name)
+                extraOpts("-Xpurge-user-libs", "-Xshort-module-name", df.name, "-Xdisable-experimental-annotation")
                 compilerOpts("-fmodules-cache-path=${project.buildDir}/clangModulesCache")
             }
         }

kotlin-native/utilities/cli-runner/src/main/kotlin/org/jetbrains/kotlin/cli/utilities/GeneratePlatformLibraries.kt

@@ -270,6 +270,7 @@ private fun generateLibrary(
                 "-compiler-option", "-fmodules-cache-path=${tmpDirectory.child("clangModulesCache").absolutePath}",
                 "-repo", outputDirectory.absolutePath,
                 "-no-default-libs", "-no-endorsed-libs", "-Xpurge-user-libs", "-nopack",
+                "-Xdisable-experimental-annotation",
                 *cinteropOptions.additionalArguments.toTypedArray(),
                 "-$SHORT_MODULE_NAME", def.shortLibraryName,
                 *def.depends.flatMap { listOf("-l", "$outputDirectory/${it.libraryName}") }.toTypedArray()