Filter comments when parsing

[JSAbrahams]

Summary

This greatly simplifies (potential) parse logic as we needn't deal with possible comment locations. We now accept that comments are not preserved in the output, however.

[codecov[bot]]

Codecov Report

Merging #381 (7705e83) into develop (63cc218) will decrease coverage by 0.04%. The diff coverage is 85.18%.

@@             Coverage Diff             @@
##           develop     #381      +/-   ##
===========================================
- Coverage    87.00%   86.96%   -0.05%     
===========================================
  Files          109      109              
  Lines        11950    11950              
===========================================
- Hits         10397    10392       -5     
- Misses        1553     1558       +5     

Impacted Files	Coverage Δ
src/check/ast/mod.rs	93.69% <ø> (-0.06%)	:arrow_down:
src/check/context/clss/generic.rs	93.18% <ø> (ø)
src/generate/ast/mod.rs	92.82% <ø> (-0.04%)	:arrow_down:
src/generate/ast/node.rs	77.69% <ø> (+0.59%)	:arrow_up:
src/parse/ast/mod.rs	100.00% <ø> (ø)
src/parse/ast/node.rs	79.77% <0.00%> (-0.11%)	:arrow_down:
src/parse/block.rs	100.00% <ø> (ø)
src/parse/mod.rs	75.00% <83.33%> (+1.31%)	:arrow_up:
src/parse/expr_or_stmt.rs	94.38% <87.50%> (-0.62%)	:arrow_down:
src/check/ast/node.rs	95.75% <100.00%> (-0.02%)	:arrow_down:
... and 5 more