Write C++ the right way

[SuperFola]

Is your feature request related to a problem?

If you are developing blindly, without any tool guidance, you are doing C++ wrong. Think of these tools like a backup camera in your car. Certainly you can back up without a camera, but having one gives you a second set of eyes, deeper into the action than is possible with your human eyes.
lefticus/cpp_weekly#175

Describe the solution you would like

Implement as much as possible from this list: lefticus/cpp_weekly#175

• add CI
• setup tests (use something like approval tests if starting with existing code)
  • related to:
  • Macro processor segfaults when using undefined symbol #409
  • Null characters are crashing the VM #410
  • Segfault with "big" numbers #403
  • Tests for failure #328
  • Add more tests #260
• enable as many warnings as possible:
  • Enable -Wall -Wextra -Wshadow -Wconversion -Wpedantic #460
• turn on warnings as errors
• add 2 (or more) compilers
• add static analysis tools
  • should run in the CI
  • static analysis should run on each commit through precommit #461
• enable runtime analysis
  • valgrind
  • sanitizers:
    • ASAN (ASAN/UBSAN do not work with GCC #396)
    • MSAN
    • UBSAN (ASAN/UBSAN do not work with GCC #396)
    • TSAN
• enable fuzzing (CI: add a fuzzing step #422)
  • I want to mark this as done because we have everything needed for fuzzing, but I'm running it once in a while (i.e. not every time a new commit is pushed to dev), but you tell me

Is it a big modification to the language? Leave it if you don't know

• Breaking change
• Compiler/syntax modifications
• Runtime modifications (standard library, modules, packages...)

[SuperFola]

This can be broken in multiple PRs as it can represent a huge amount of work.