Cleanups: Test code using ranges as an identifier, plus more

[StephanTLavavej]

• P2321R2_views_zip was using ranges as an identifier. 🙀 Rename this to rngs, avoiding confusion.
• Dev09_192736_tr1_prngs_not_copyconstructible, written a billion years ago, also had ranges. While this isn't really a problem, let's add a d suffix (also to the following weights), which is consistent with the preceding and following vector<float> rangesf and vector<long double> rangesl.
• Dev09_056375_locale_cleanup, written a trillion years ago, could use some extremely minor cleanups:
  • Add preprocessor comments.
  • Drop a totally unnecessary using-directive.
    • In general, we should be wary of changing tests in ways that could disturb what they were testing, but there is no way that this had any effect, being scoped to main().
  • Change a C cast to reinterpret_cast.

[StephanTLavavej]

I'm mirroring this to the MSVC-internal repo - please notify me if any further changes are pushed.