Partial Application Syntax: Stage 1 (#9343)

* add partial application syntax and some tests

* remove unnecessary error message and hasPartial function from parseNewArguments

* add types for PartialExpression

* Update the tests

* rename PartialExpression to Partial

* move Partial from expressions to types and rename to ArgumentPlaceholder

* add tests for ArgumentPlaceholder in babel-generator

* rename Partial to ArgumentPlaceholder

* update the tests

* remove alias from the type and undo changes in generated folder

* adds a nice error message

* better definition for the type

* auto-generated files

* update the conditional for allowPlaceholder message and tests

* update CallExpression definition to accept ArgumentPlaceholder

* change description

* clean up

* indent ArgumentPlaceholder entry and revert unwanted changes

packages/babel-plugin-syntax-partial-application/src/index.js

@@ -0,0 +1,13 @@
+import { declare } from "@babel/helper-plugin-utils";
+
+export default declare(api => {
+  api.assertVersion(7);
+
+  return {
+    name: "syntax-partial-application",
+
+    manipulateOptions(opts, parserOpts) {
+      parserOpts.plugins.push("partialApplication");
+    },
+  };
+});