Daniel Andersson
e7fb1c8516
Using volatile on a word size location will generate a single move instruction without order guarantees and is supported on all compilers. Replace FetchAndAdd with FetchAndDecrement, since the latter is sufficient and eaiser to implement portably (in particular on some Windows setups). BUG=https://github.com/dart-lang/sdk/issues/24049 R=iposva@google.com Review URL: https://codereview.chromium.org//1287853005 .