fix compiler warnings from HiGHS 1.10.0

[svigerske]

This fixes again compiler warnings

• on defining public functions without declaring them first, by either making them static or adding the declaration, and
• on unused variables (i_clock is assigned by not used if NDEBUG is defined)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.06%. Comparing base (5e7f6f3) to head (2200b6f).
Report is 18 commits behind head on latest.

Additional details and impacted files

@@            Coverage Diff             @@
##           latest    #2344      +/-   ##
==========================================
- Coverage   79.26%   79.06%   -0.21%     
==========================================
  Files         345      345              
  Lines       84363    84387      +24     
==========================================
- Hits        66874    66720     -154     
- Misses      17489    17667     +178     

☔ 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.

[galabovaa]

Hi Stefan,

Thank you for these! Just for reference, which compiler / OS combination do you use to check?

[svigerske]

We compile HiGHS with GCC 14 with -Wall -Wreturn-type -Wmissing-declarations -std=c++11 -Wno-unused-variable -Wno-unused-but-set-variable -Wno-comment on Linux.

That we enable -Wmissing-declarations raised new warnings with every HiGHS update, which I then fix. But some of these -Wno-... are only added because it seemed a lot of work to fix all the warnings in the code.

This HighsTimer.h gets compiled in another code as well, one where we don't use -Wno-unused-variable.