Make llvm build options match emscripten forge recipe

[mcbarton]

Description

Please include a summary of changes, motivation and context for this PR.

This PR will make the llvm build options match the emscripten forge recipe

Fixes # (issue)

Type of change

Please tick all options which are relevant.

• Bug fix
• New feature
• Requires documentation updates

Testing

Please describe the test(s) that you added and ran to verify your changes.

Checklist

• I have read the contribution guide recently

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 70.87%. Comparing base (8c0cd6d) to head (4f865d4).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #416   +/-   ##
=======================================
  Coverage   70.87%   70.87%           
=======================================
  Files           9        9           
  Lines        3533     3533           
=======================================
  Hits         2504     2504           
  Misses       1029     1029           

[vgvassilev]

LGTM!