Merge acorn 0.12.1 and acorn-babel (formerly "embed acorn" in the original git history).

test/tests.js

@@ -28682,7 +28682,39 @@ test("const x = 14, y = 3, z = 1977", {
 
 testFail("const a;", "Unexpected token (1:7)", {ecmaVersion: 6});
 
-testFail("for(const x = 0;;);", "Unexpected token (1:4)", {ecmaVersion: 6});
+test("for(const x = 0;;);", {
+  type: "Program",
+  body: [{
+    type: "ForStatement",
+    init: {
+      type: "VariableDeclaration",
+      declarations: [{
+        type: "VariableDeclarator",
+        id: {
+          type: "Identifier",
+          name: "x",
+          range: [10, 11]
+        },
+        init: {
+          type: "Literal",
+          value: 0,
+          range: [14, 15]
+        },
+        range: [10, 15]
+      }],
+      kind: "const",
+      range: [4, 15]
+    },
+    test: null,
+    update: null,
+    body: {
+      type: "EmptyStatement",
+      range: [18, 19]
+    },
+    range: [0, 19]
+  }],
+  range: [0, 19]
+}, {ecmaVersion: 6, ranges: true});
 
 testFail("for(x of a);", "Unexpected token (1:6)");
 
@@ -28914,3 +28946,22 @@ test("function f() {} / 1 /", {
     }
   ]
 });
+
+var semicolons = []
+testAssert("var x\nreturn\n10", function() {
+  var result = semicolons.join(" ");
+  semicolons.length = 0;
+  if (result != "5 12 15")
+    return "Unexpected result for onInsertedSemicolon: " + result;
+}, {onInsertedSemicolon: function(pos) { semicolons.push(pos); },
+    allowReturnOutsideFunction: true,
+    loose: false})
+
+var trailingCommas = []
+testAssert("[1,2,] + {foo: 1,}", function() {
+  var result = trailingCommas.join(" ");
+  trailingCommas.length = 0;
+  if (result != "4 16")
+    return "Unexpected result for onTrailingComma: " + result;
+}, {onTrailingComma: function(pos) { trailingCommas.push(pos); },
+    loose: false})