Add atomic.fence instruction (#2307)

This adds `atomic.fence` instruction:
https://github.com/WebAssembly/threads/blob/master/proposals/threads/Overview.md#fence-operator

This also fix bugs in `atomic.wait` and `atomic.notify` instructions in
binaryen.js and adds tests for them.

1 files changed, 4 insertions, 4 deletions

diff --git a/test/binaryen.js/exception-handling.js.txt b/test/binaryen.js/exception-handling.js.txt
index cdf45aeaa..463743ff6 100644
--- a/test/binaryen.js/exception-handling.js.txt
+++ b/test/binaryen.js/exception-handling.js.txt
@@ -26,7 +26,7 @@
  )
 )
 
-getExpressionInfo(throw) = {"id":39,"type":8,"event":"e"}
-getExpressionInfo(br_on_exn) = {"id":41,"type":7,"name":"l","event":"e"}
-getExpressionInfo(rethrow) = {"id":40,"type":8}
-getExpressionInfo(try) = {"id":38,"type":0}
+getExpressionInfo(throw) = {"id":40,"type":8,"event":"e"}
+getExpressionInfo(br_on_exn) = {"id":42,"type":7,"name":"l","event":"e"}
+getExpressionInfo(rethrow) = {"id":41,"type":8}
+getExpressionInfo(try) = {"id":39,"type":0}