Performance improvements

[manofstick]

Fixed a number of issues with performance.

Project:

• Added a mechanism using [ReflectedDefintion] that compares both output results and times of properly compiled code and linq compiled code. Added a "Performance" project configuration to run the time portion of these tests (it always runs the comparison code)

Expression Tree Creation:

• Very slow when capturing state in Expression.Lambda calls; so compiled Expression.Lambdas individually and stored in objects which included captured state
• Performance of basic operators was very slow because custom method was provided so I skip that in case of primitive types
• Using Blocks in a couple more places

Analysis Time:

• DerivedPatterns.SpecificCall was v. slow, so removed
• A few other Expr tree manipulations; removing |> and |< and then fixing resultant tree
• Removing op_Range and op_RangeStep as the offered functions are v. slow

Now in many cases get close to compile time speeds (so this library is actually semi-useable!), but could still do with another full round of examination as I know I have left holes, as well as missing functionality (recursive functions to name one big hole that I haven't peered down yet). Hopefully I'll make some time; but I'm pretty burnt out at the moment.

[manofstick]

@fsgit

Not sure if anyone is having a look at this; so maybe let me know if you want a stable merge point, or otherwise I'll just bleed things in as my time takes me...

Anyway, just as an example of the speed increase, the tests in FSharp.Quotations.Evaluator.Unittests on my machine previously took around 22 seconds, and now take ~ 1 second. (this was in the 64-bit JIT; in 32-bit JIT it previously around 8 seconds, now around 1.5 seconds)

...and in complex quotations, with a number of functions and currying, the improvements were much greater (although if there are more than 5 arguments or 8 captured variables then some of my optimizations drop back to original functionality; I could enhance this; these were just the easy values, have to think a bit more to increase these...)

[bleis-tift]

In complex quotations that throw StackOverflowException, this PR solve the problem.

[manofstick]

@bleis-tift

Thanks for that; shame I didn't branch from that version! I'll see how I go merging in it in my fork over the w/end.

[dsyme]

Hi guys,

I think it would make sense to bring one of you on board to have the ability to accept pull requests and release nuget packages. Could you email myself (donsyme AT fastmail DOT fm) and @forki (sforkmann AT gmail DOT com) if you're interested

Thanks
Don