Bug 1001090 - Part 1: Implement let temporal dead zone in the frontend and interpreter.
Bug 1001090 - Part 2a: Compile new let opcodes in Baseline.
Bug 1001090 - Part 2b: Fix unwinding all scopes to not use pc. (r=jimb)
Bug 1001090 - Part 3: Compile new let opcodes in Ion.
Bug 1001090 - Part 4: Fix errors in addon-sdk/ (r=zombie)
Bug 1001090 - Part 4: Fix errors in browser/base/ (r=gavin)
Bug 1001090 - Part 4: Fix errors in browser/devtools/ and toolkit/devtools/ (r=fitzgen)
Bug 1001090 - Part 4: Fix errors in dom/browser-element/
Bug 1001090 - Part 4: Fix errors in dom/contacts/ (r=gwagner)
Bug 1001090 - Part 4: Fix errors in services/crypto/ (r=gavin)
Bug 1001090 - Part 4: Fix errors in services/healthreport/ (r=gavin)
Bug 1001090 - Part 4: Fix errors in services/sync/ (r=gavin)
Bug 1001090 - Part 4: Fix errors in testing/marionette/ (r=gavin)
Bug 1001090 - Part 4: Fix errors in toolkit/components/contentprefs/ (r=gavin)
Bug 1001090 - Part 4: Fix errors in toolkit/components/crashes/ (r=gavin)
Bug 1001090 - Part 4: Fix errors in toolkit/components/passwordmgr/ (r=mrbkap)
Bug 1001090 - Part 4: Fix errors in Sqlite.jsm (r=gavin)
Bug 1001090 - Part 4: Fix errors in AddonRepository.jsm (r=gavin)
Bug 1001090 - Part 4: Fix errors in PlacesTransactions.jsm
Bug 1001090 - Part 4: Fix errors in aboutMemory.js (r=njn)