[R] Remove usage of cpp11's `HAS_UNWIND_PROTECT`

[DavisVaughan]

Describe the enhancement requested

cpp11 is bumping to require R >=4.0.0 in the next release r-lib/cpp11#411

That means that R_UnwindProtect() is always available, and the macro HAS_UNWIND_PROTECT is no longer needed. I'm going to keep it around for a release or two, but if you could remove your reliance on it, then that'd be great!

arrow/r/src/safe-call-into-r-impl.cpp

Line 49 in 50f2d6e

#if defined(HAS_UNWIND_PROTECT)

Component(s)

R

[assignUser]

Thanks for the early warning, should be easy enough to remove.

We just finished a release so the change will only hit CRAN after the next release, so probably February, is that ok?

[DavisVaughan]

Sure, no big rush on my end!

[assignUser]

Issue resolved by pull request 45261
#45261