[JS IR] Introduce the GENERATE_INLINE_ANONYMOUS_FUNCTIONS feature flag

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/directives/JsEnvironmentConfigurationDirectives.kt

@@ -112,6 +112,11 @@ object JsEnvironmentConfigurationDirectives : SimpleDirectivesContainer() {
         applicability = DirectiveApplicability.Global
     )
 
+    val GENERATE_INLINE_ANONYMOUS_FUNCTIONS by directive(
+        description = "translate lambdas into in-line anonymous functions",
+        applicability = DirectiveApplicability.Global
+    )
+
     val SAFE_EXTERNAL_BOOLEAN by directive(
         description = "",
         applicability = DirectiveApplicability.Global

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/services/CompilerConfigurationProvider.kt

@@ -120,6 +120,10 @@ fun createCompilerConfiguration(module: TestModule, configurators: List<Abstract
         configuration.put(JSConfigurationKeys.PROPERTY_LAZY_INITIALIZATION, true)
     }
 
+    if (JsEnvironmentConfigurationDirectives.GENERATE_INLINE_ANONYMOUS_FUNCTIONS in module.directives) {
+        configuration.put(JSConfigurationKeys.GENERATE_INLINE_ANONYMOUS_FUNCTIONS, true)
+    }
+
     if (module.frontendKind == FrontendKinds.FIR) {
         configuration[CommonConfigurationKeys.USE_FIR] = true
     }