Fix tokenizing of slash after propery with keyword name

FIX: Fix an issue where a slash after a call to a propery named the same
as some keywords would be tokenized as a regular expression.

Closes #1232

acorn-loose/src/expression.js

@@ -519,6 +519,7 @@ lp.parsePropertyAccessor = function() {
 lp.parseIdent = function() {
   let name = this.tok.type === tt.name ? this.tok.value : this.tok.type.keyword
   if (!name) return this.dummyIdent()
+  if (this.tok.type.keyword) this.toks.type = tt.name
   let node = this.startNode()
   this.next()
   node.name = name

acorn/src/expression.js

@@ -1059,6 +1059,7 @@ pp.parseIdentNode = function() {
       (this.lastTokEnd !== this.lastTokStart + 1 || this.input.charCodeAt(this.lastTokStart) !== 46)) {
       this.context.pop()
     }
+    this.type = tt.name
   } else {
     this.unexpected()
   }

test/tests.js

@@ -29929,3 +29929,40 @@ test(`typeof async function f(){}
 
 testFail(`typeof async function f(){}
 /foo/`, "Unexpected token (2:5)", { ecmaVersion: 8, locations: true })
+
+test("foo.if() / 2", {
+  type: "Program",
+  body: [
+    {
+      type: "ExpressionStatement",
+      expression: {
+        type: "BinaryExpression",
+        left: {
+          type: "CallExpression",
+          callee: {
+            type: "MemberExpression",
+            object: {
+              type: "Identifier",
+              name: "foo"
+            },
+            property: {
+              type: "Identifier",
+              name: "if"
+            },
+            computed: false
+          },
+          arguments: []
+        },
+        operator: "/",
+        right: {
+          type: "Literal",
+          value: 2,
+          raw: "2"
+        }
+      }
+    }
+  ],
+  sourceType: "script"
+}, {
+  ecmaVersion: 5
+})