Removed '_|_' as a built in declaration and renamed it to 'Void',
'FalseElim' now 'VoidElim' to match up
Renamed VoidElim to void in order to ensure further consistency
Allow Partial Eval of lambdas/lets in static pos
Merge pull request #1619 from ahmadsalim/feature/renamevoid

Removed `_|_` as a built in declaration and renamed it to `Void`
Merge pull request #1630 from edwinb/partial-eval

Allow Partial Eval of lambdas/lets in static pos