LGTM
http://codereview.chromium.org/8635/diff/208/210
File src/ast.h (right):
http://codereview.chromium.org/8635/diff/208/210#newcode1344
Line 1344: };
Now we have back-references with an index, the capture should hold the
matching index, so we can pair captures and back-references.
http://co
http://codereview.chromium.org/8635/diff/208/212
File src/parser.cc (right):
http://codereview.chromium.org/8635/diff/208/212#newcode3244
Line 3244: next_ = in()->GetNext();
We know it will work because we advance twice after setting up the
pushback buffer.
http://codereview.chromium.org/8635/d
