implement AST_Yield spidermonkey AST

lib/mozilla-ast.js

@@ -464,6 +464,7 @@
     map("ForInStatement", AST_ForIn, "left>init, right>object, body>body");
     map("ForOfStatement", AST_ForOf, "left>init, right>object, body>body");
     map("AwaitExpression", AST_Await, "argument>expression");
+    map("YieldExpression", AST_Yield, "argument>expression, delegate=is_star");
     map("DebuggerStatement", AST_Debugger);
     map("VariableDeclarator", AST_VarDef, "id>name, init>value");
     map("CatchClause", AST_Catch, "param>argname, body%body");

lib/parse.js

@@ -1726,6 +1726,7 @@ function parse($TEXT, options) {
             croak("Unexpected yield expression outside generator function",
                 S.prev.line, S.prev.col, S.prev.pos);
         }
+        var start = S.token;
         var star = false;
         var has_expression = true;
 
@@ -1749,8 +1750,10 @@ function parse($TEXT, options) {
         }
 
         return new AST_Yield({
+            start      : start,
             is_star    : star,
-            expression : has_expression ? expression() : null
+            expression : has_expression ? expression() : null,
+            end        : prev()
         });
     }
 

test/input/spidermonkey/input.js

@@ -17,10 +17,13 @@ export {A1, B1} from "a.js";
 export {C};
 
 (a, [b], {c:foo = 3}, ...d) => null;
-() => {}
+() => {};
 
 async function f() { }
-function*gen() { }
+function*gen() {
+    yield 1;
+    yield* 2;
+}
 
 class Class extends Object {
     constructor(...args) {