Add irMinimum option

[cgewecke]

#895

Adds a convenience option irMinimum which configures solc to compile using the same config Zeppelin is currently using - they use viaIR normally but can get away with irMinimum.

Execution speeds locally were very similar to what they're seeing in CI (~12 min) and the job completed without problems. (Using full viaIR the machine stalls out during sorting tests which run hundreds of loop iterations).

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.63%. Comparing base (e2126e7) to head (1c14ea4).

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #907      +/-   ##
==========================================
+ Coverage   96.62%   96.63%   +0.01%     
==========================================
  Files          19       19              
  Lines        1066     1071       +5     
==========================================
+ Hits         1030     1035       +5     
  Misses         36       36              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.