Julia remove globals

[davidmclifton]

Removed non-static globals and put them in a structure which is passed, so should not be multithreading safe. Also did some performance optimizations.

Results of optimizations are:

BEFORE:

julia> @benchmark SyntaxParser.parse("5 + 5")
BenchmarkTools.Trial: 10000 samples with 1 evaluation.
Range (min … max): 18.917 μs … 2.400 ms ┊ GC (min … max): 0.00% … 98.15%
Time (median): 20.500 μs ┊ GC (median): 0.00%
Time (mean ± σ): 22.406 μs ± 63.097 μs ┊ GC (mean ± σ): 7.87% ± 2.77%

Memory estimate: 37.61 KiB, allocs estimate: 200.

AFTER:

julia> @benchmark SyntaxParser.parse("5 + 5")
BenchmarkTools.Trial: 10000 samples with 3 evaluations.
Range (min … max): 8.361 μs … 874.167 μs ┊ GC (min … max): 0.00% … 98.16%
Time (median): 9.833 μs ┊ GC (median): 0.00%
Time (mean ± σ): 11.513 μs ± 35.497 μs ┊ GC (mean ± σ): 13.35% ± 4.27%

Memory estimate: 28.77 KiB, allocs estimate: 96.

[DmitrySoshnikov]

Perfect, thanks!