Merge pull request mozilla#325 from fitzgen/update-mappings-wasm

Update lib/mappings.wasm to 0.5.0

Author: fitzgen

bench/bench-dom-bindings.js

@@ -1,5 +1,5 @@
 sourceMap.SourceMapConsumer.initialize({
-  "lib/mappings.wasm": "../lib/mappings.wasm",
+  "lib/mappings.wasm": "../lib/mappings.wasm?bust_cache=" + String(Math.random()).replace(/0\./, ""),
 });
 
 function bindRange(labelId, updater) {