This is meant for users making custom builds to match the options used on
optimized, official builds.
This enables, on the platforms which support them:
- `use_static_cpp=yes` (portable binaries for Linux and Windows)
- `use_lto=yes` (link time optimizations - note: requires a lot of RAM!)
- `debug_symbols=no` (no debug symbols, smaller binaries)
Also abort when using MSVC with `production=yes`, as:
- It cannot optimize the GDScript VM like GCC or Clang do, leading to
significant performance drops.
- Its LTO support is unreliable, at least used to trigger crashes last
we tried it extensively.
All options can still be overridden if specified, and the `dev=yes` option
was changed to also support overrides.
(cherry picked from commit db26871210)
f3c030aa47
