Parse parameter decorators outside of Await context when appropriate (#50040)

tests/cases/conformance/decorators/class/method/parameter/decoratorOnClassMethodParameter3.ts

@@ -0,0 +1,11 @@
+// @target: es2015
+// @experimentaldecorators: true
+
+// https://github.com/microsoft/TypeScript/issues/48509
+declare function dec(a: any): any;
+function fn(value: Promise<number>): any {
+  class Class {
+    async method(@dec(await value) arg: number) {}
+  }
+  return Class
+}