Optimize F# tupled and curried arguments and local functions

[Jand42]

A lot of FSharp.Core functions like Seq.map2 take a curried function parameter, but implementation always applies it fully. Adding an optimization is possible that JS translation will take a flat 2-argument function. Same for tupled function arguments. Information about tuple/curried function argument optimization is added to metadata.

Further, local tupled/curried functions can be optimized to flat form not only if they are only used locally, but when they are also passed to functions that are accepting the optimized form.

[Jand42]

A new component is ArgCurrying module in WS.Compiler.FSharp. It is analyzing methods/constructors with function arguments to check what length do they apply them and where they are passed around. A curried function can be optimized to flat but not the other way around to keep semantics.

Metadata contains purity and currying information in a new Optimizations class.

Local curried/tupled functions are converted to flat and currying/decurrying and tupling/detupling pairs are erased.

Optimizations are now run in a few more steps:

• simplify let expressions (inlining when possible)
• erase calls to Runtime.x functions where possible (needs the inlining so argument is in correct place)
• recursive simplify optimizations
• break to statement-based form (remove forms not compatible with JS.Writer) - skip this for inlines
• use Runtime.Curried helper when curried forms remained

Added some tests for compilation in WS.Tests\Compiler.fs. These look at metadata (all expressions now retained in memory) to check for optimizations taking place.