de-optimized math replacements / idiom detection

[psifertex]

Compilers do lots of fun things to calculate modulo or division with shifts and multiplication. We need a new optimization pass which will replace these more opaque operations with simplified expressions.

See:

https://zneak.github.io/fcd/2017/02/19/divisions.html
https://github.com/hcs0/Hackers-Delight

And a previous plugin that simply annotates with a comment:
https://github.com/cah011/binja-div

[psifertex]

Interesting clang examples: https://twitter.com/whitequark/status/1338709746619088896

[psifertex]

Another relevant plugin: https://github.com/jmprdi/binja-division-deoptimization

[D0ntPanic]

Simplification of optimized division and modulus has been added in build 3.5.4311

Not all division and modulus code patterns currently simplify. The following issues track cases that are not yet handled:

#4362: Optimized modulus using a combination of divide and shifted multiply with masking of low bits
#4363: Optimized modulus using arithmetic of mixed integer sizes
#4364: Optimized division and modulus are not simplified on armv7
#4365: Indirect sign extension through variable for dividend in optimized divide
#4366: Unsigned shift of signed value during optimized signed divide that is only valid because of additional multiplication
#4367: Use of partially written variable during optimized divide