PR #89452 made assumptions on comparing paths as strings
which doesn't work when composing them as POSIX paths (`/`)
but processing them on NT (`\`, `\\`).
Previously, all of the code generation routines would just needlessly
write the same files over and over, even when not needed.
This became a problem with the advent of the experimental ninja backend
for SCons, which can be trivially enabled with a few lines of code and
relies on timestamp changes, making it thus impractical.
Verbose output is meant for debugging the SCU mode itself and can be
triggered by changing the `_verbose` bool manually.
Prefix all prints with "SCU:" for context, and print the processed
folders all at once instead of when adding the sources.
The UWP platform port was never ported to the Godot 4.0+ API,
and it's now accumulating bitrot as it doesn't compile, and thus
we no longer propagate platform changes in it.
So we finally remove to acknowledge this state. There's still some
interest in reviving the UWP port eventually, especially as support
for Direct3D 12 will soon be merged, but when that happens it will
be easiest to redo it from scratch.
"scu_limit" allows specifying the maximum number of includes in a single SCU file (translation unit). A lower limit (e.g. 8) uses less RAM during compilation, but may be slower to compile.