Parser refactoring (#11871)

* refactor: parseMaybeUnary => parseUnary

* refactor: extract shouldExitDescending method

* refactor: add parseUpdate

* refactor: avoid comparing with hardcoded token value

* refactor: add ParseNewOrNewTarget

* refactor: add parseCoverCallAndAsyncArrowHead

* add parseBind

* refactor: polish parseTaggedTemplateExpression interface

* refactor: add parseMember method

* refactor: add parseSuper method

* refactor: add parseAsyncArrowUnaryFunction method

* fix: disallow line break before async binding arrow

* refactor: simplify tt.name logic

* refactor: add parseDo method

* refactor: misc

* refactor: rename parseObjectMember by parsePropertyDefinition

* refactor: unify set/get/async keyword parsing in ObjectMethod

* refactor: misc

* refactor: add parseArrayLike method

* refactor: move fsharp epilogure and prologue inside parseObjectLike

* fixup

* refactor: rename parseFunctionExpression to parseFunctionOrFunctionSent

* refactor: remove redundant logic

* refactor: rename parseClassPropertyName by parseClassElementName

* refactor: avoid unecessary lookahead when parsing tt._export

* fix: export-default-from should support escaped async as export binding

* address review comments

* parseUnary -> parseMaybeUnary

packages/babel-parser/test/fixtures/es2017/async-functions/invalid-escape-export-async-function/options.json

@@ -1,3 +1,3 @@
 {
   "throws": "Unexpected token, expected \"{\" (1:7)"
-}
+}

packages/babel-parser/test/fixtures/es2017/async-functions/newline-before-arrow/input.js

@@ -0,0 +1,2 @@
+async x
+=> x

packages/babel-parser/test/fixtures/es2017/async-functions/newline-before-arrow/output.json

@@ -0,0 +1,39 @@
+{
+  "type": "File",
+  "start":0,"end":12,"loc":{"start":{"line":1,"column":0},"end":{"line":2,"column":4}},
+  "errors": [
+    "SyntaxError: No line break is allowed before '=>' (2:2)"
+  ],
+  "program": {
+    "type": "Program",
+    "start":0,"end":12,"loc":{"start":{"line":1,"column":0},"end":{"line":2,"column":4}},
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start":0,"end":12,"loc":{"start":{"line":1,"column":0},"end":{"line":2,"column":4}},
+        "expression": {
+          "type": "ArrowFunctionExpression",
+          "start":0,"end":12,"loc":{"start":{"line":1,"column":0},"end":{"line":2,"column":4}},
+          "id": null,
+          "generator": false,
+          "async": true,
+          "params": [
+            {
+              "type": "Identifier",
+              "start":6,"end":7,"loc":{"start":{"line":1,"column":6},"end":{"line":1,"column":7},"identifierName":"x"},
+              "name": "x"
+            }
+          ],
+          "body": {
+            "type": "Identifier",
+            "start":11,"end":12,"loc":{"start":{"line":2,"column":3},"end":{"line":2,"column":4},"identifierName":"x"},
+            "name": "x"
+          }
+        }
+      }
+    ],
+    "directives": []
+  }
+}