Implement comparison Ops, fix bug with branch table target tracking, add benchmark.

[twitchyliquid64]

• Implements greater-than, less-than etc ops
• Fixed a bug where branch table jump addresses were not being tracked, causing the scanner to emit invalid candidates
• Created an ideal-case benchmark for Native vs Interpreted execution modes.

On my i7 2nd gen:

[xxx@xxx]:~/projects/wagon> go test -bench=BenchmarkU64Arithmetic github.com/go-interpreter/wagon/exec
goos: linux
goarch: amd64
pkg: github.com/go-interpreter/wagon/exec
BenchmarkU64Arithmetic10Interpreted-8   	  100000	     16611 ns/op
BenchmarkU64Arithmetic10Native-8        	  200000	      5781 ns/op
BenchmarkU64Arithmetic50Interpreted-8   	   20000	     76431 ns/op
BenchmarkU64Arithmetic50Native-8        	   50000	     25961 ns/op
PASS
ok  	github.com/go-interpreter/wagon/exec	7.565s

So currently 3x, but heaps of room for improvement (I think I can cut emitted assembly by 80%, and theres still heaps of opcodes we dont yet support). I'm expecting we should be able to hit 10-20x here.

[codecov-io]

Codecov Report

Merging #119 into master will increase coverage by 0.37%.
The diff coverage is 73.59%.

@@            Coverage Diff             @@
##           master     #119      +/-   ##
==========================================
+ Coverage   65.61%   65.98%   +0.37%     
==========================================
  Files          41       41              
  Lines        3949     4066     +117     
==========================================
+ Hits         2591     2683      +92     
- Misses       1091     1116      +25     
  Partials      267      267

Impacted Files	Coverage Δ
exec/internal/compile/compile.go	0% <0%> (ø)	⬆️
exec/internal/compile/scanner.go	0% <0%> (ø)	⬆️
exec/internal/compile/backend_amd64.go	79.46% <81.41%> (+0.84%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 89a7df5...fcdae72. Read the comment docs.

[twitchyliquid64]

✈️ 🦄