Calculate CLOCK_IN_MS via floats

[mbarbar]

Otherwise we're dealing with truncation, particularly problematic when CLOCKS_PER_SEC is less than TIMEINTERVAL.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 64.45%. Comparing base (5c45081) to head (b2b44c6).
⚠️ Report is 8 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1834   +/-   ##
=======================================
  Coverage   64.44%   64.45%           
=======================================
  Files         252      252           
  Lines       25208    25210    +2     
  Branches     4768     4768           
=======================================
+ Hits        16246    16248    +2     
  Misses       8962     8962           

Files with missing lines	Coverage Δ
svf/include/SVFIR/SVFType.h	95.65% <ø> (ø)

... and 9 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.