* Don't implement Eq and Hash for EntityList
* Generate eq and hash methods for InstructionData
* Use the eq() and hash() methods of InstructionData in simple_gvn
* Update to rustfmt-preview.
* Run "cargo fmt --all" with rustfmt 0.4.1.
rustfmt 0.4.1 is the latest release of rustfmt-preview available on the
stable channel.
* Fix a long line that rustfmt 0.4.1 can't handle.
* Remove unneeded commas left behind by rustfmt.