Add test_tsan target to Makefile

[norio-nomura]

No description provided.

[norio-nomura]

This is preparation for #2089.
Since the issue is caused by SourceKitten, it will need updating SourceKitten to fix #2089.
So, after confirming that test_tsan fails on CircleCI, disable that step in CircleCI.

[codecov-io]

Codecov Report

Merging #2092 into master will increase coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2092      +/-   ##
==========================================
+ Coverage   89.68%   89.69%   +0.01%     
==========================================
  Files         259      259              
  Lines       15015    15015              
  Branches      977      977              
==========================================
+ Hits        13466    13468       +2     
+ Misses       1532     1530       -2     
  Partials       17       17

Impacted Files	Coverage Δ
Source/SwiftLintFramework/Models/Command.swift	97.82% <0%> (+2.17%)	⬆️

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[jpsim]

Nice work! Although let's not merge until it passes.

[norio-nomura]

Rebased and enabled on CircleCI.

[jpsim]

Nice! It must have been tricky to figure out exactly what the magic compiler flags needed to be!