Opt-in ExperimentalWasmJsInterop annotation (#319)

* Opt-in ExperimentalWasmJsInterop annotation

* fixup! Opt-in ExperimentalWasmJsInterop annotation

Author: fzhinkin

runtime/build.gradle.kts

@@ -1,5 +1,6 @@
 import org.jetbrains.kotlin.gradle.ExperimentalKotlinGradlePluginApi
 import org.jetbrains.kotlin.gradle.ExperimentalWasmDsl
+import org.jetbrains.kotlin.gradle.plugin.KotlinPlatformType
 import org.jetbrains.kotlin.gradle.tasks.KotlinNativeCompile
 import java.util.*
 
@@ -71,6 +72,11 @@ kotlin {
                     )
                 }
             }
+            if (target.platformType == KotlinPlatformType.wasm) {
+                compileTaskProvider.configure {
+                    compilerOptions.optIn.add("kotlin.js.ExperimentalWasmJsInterop")
+                }
+            }
         }
     }