Allow comments in roxygen comment blocks

[lorenzwalthert]

Closes #828, but more generally adds support for random comments in roxygen code blocks. Cases were internally distinct in emulate_rd() depending on the presence of special characters like %, which is why only a %>% triggered a problem.

[codecov-commenter]

Codecov Report

Merging #830 (2444974) into master (66ce587) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #830      +/-   ##
==========================================
+ Coverage   90.49%   90.53%   +0.03%     
==========================================
  Files          47       47              
  Lines        2441     2451      +10     
==========================================
+ Hits         2209     2219      +10     
  Misses        232      232              

Impacted Files	Coverage Δ
R/roxygen-examples-add-remove.R	95.45% <100.00%> (+3.14%)	⬆️
R/roxygen-examples-parse.R	96.72% <100.00%> (+0.05%)	⬆️
R/roxygen-examples.R	97.91% <100.00%> (ø)

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[github-actions]

This is how benchmark results would change (along with a 95% confience interval in relative change) if 8468581 is merged into master:

• cache_applying: 0.1s -> 0.1s [-3.91%, +7.47%]
• cache_recording: 1.44s -> 1.44s [-0.86%, +1.27%]
• without_cache: 3.68s -> 3.68s [-1.01%, +1.05%]

Further explanation regarding interpretation and methodology can be found in the documentation.

[github-actions]

This is how benchmark results would change (along with a 95% confience interval in relative change) if fa83546 is merged into master:

• cache_applying: 0.09s -> 0.09s [-5.82%, +4.83%]
• cache_recording: 1.13s -> 1.13s [-0.27%, +0.95%]
• without_cache: 2.86s -> 2.84s [-0.75%, -0.04%]

Further explanation regarding interpretation and methodology can be found in the documentation.

[github-actions]

This is how benchmark results would change (along with a 95% confience interval in relative change) if 8812fe5 is merged into master:

• cache_applying: 0.09s -> 0.09s [-4.09%, +5.69%]
• cache_recording: 1.06s -> 1.05s [-3.01%, -0.21%]
• without_cache: 2.65s -> 2.66s [-0.66%, +0.97%]

Further explanation regarding interpretation and methodology can be found in the documentation.