Merge pull request #110 from pjonsson/more-simplification

Simplify array creation that is immediately indexed.
Add some more special cases to show instance for UntypedFeld.
Merge pull request #111 from pjonsson/more-show

Add some more special cases to show instance for UntypedFeld.
Simplify linear expressions.
Merge pull request #112 from pjonsson/simplify-linear

Simplify linear expressions.
Make ElementsFeat an explicit member of Typed

With `typeDictSym _ = Nothing`, this disables constant folding and binding of ElementsFeat expressions.
Tweak Show instance for EPar.
Optimize a || skip and skip || b in Elements.
Optimize parFor 1 e in the same way as For 1 e.
Constant fold a few simple things.
Merge pull request #113 from pjonsson/elements

Elements improvements
Implement support for 15-tuples.
Merge pull request #114 from pjonsson/fifteen-tuples

Implement support for 15-tuples.
Add more possible targets for later use.
Make it possible to use the new code motion through an option.
Merge pull request #115 from pjonsson/more-options

Enable the use of the new code motion available in Syntactic 1.12.
Make sure that the let-sinking sinks through all the parameters.

The previous implementation of let-sinking was sufficient for ensuring
invariants expected by FromCore, but it's a silly idea to stop mid-flight.
Add the Middleend support for 15-tuples.
Merge pull request #116 from pjonsson/fifteen-two

Add the Middleend support for 15-tuples.
Merge pull request #117 from pjonsson/prevent-hang

Make sure that the let-sinking sinks through all the parameters.