Fix bidi support

[nightwing]

No description provided.

[codecov]

Codecov Report

Merging #3658 into master will increase coverage by 0.05%.
The diff coverage is 31.86%.

@@            Coverage Diff            @@
##           master   #3658      +/-   ##
=========================================
+ Coverage   66.44%   66.5%   +0.05%     
=========================================
  Files         478     478              
  Lines       47613   47671      +58     
  Branches     9061    9082      +21     
=========================================
+ Hits        31638   31705      +67     
+ Misses      15975   15966       -9

Impacted Files	Coverage Δ
lib/ace/edit_session.js	82.61% <100%> (+0.77%)	⬆️
lib/ace/virtual_renderer.js	68.62% <100%> (+0.19%)	⬆️
lib/ace/lib/bidiutil.js	20.26% <25%> (+0.17%)	⬆️
lib/ace/bidihandler.js	30.05% <25.42%> (+2.37%)	⬆️
lib/ace/layer/marker.js	65.44% <40%> (-7.21%)	⬇️
lib/ace/layer/gutter.js	64.74% <0%> (+0.35%)	⬆️
lib/ace/layer/cursor.js	85.61% <0%> (+0.71%)	⬆️
lib/ace/line_widgets.js	57.67% <0%> (+14.1%)	⬆️

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[dometto]

@nightwing thanks for this great PR. I have the impression RTL support almost works: at the moment, pressing enter while on an RTL line incorrectly produces a new LTR line. Looking at the source, the RTL extension is supposed to prevent that with this function:
https://github.com/ajaxorg/ace/pull/3658/files#diff-39037390fecdb74f84f14bc14e4a5e1dR85
But that function never appears to be called (when I add a debug statement to it, it doesn't appear when I insert a newline on an RTL line). Am I doing something wrong, or is this a bug?