[libc] [llvm] [libc] enable stack protectors and frame pointers on default (PR #86288)

[Nick Desaulniers via llvm-commits]

https://github.com/nickdesaulniers commented:

Stack protectors are just good practice. +1

I believe our internal customer that's using bazel is using frame pointers generally, so this LGTM.

Do we document these cmake options anywhere?  Might be nice to mention them somewhere, so that folks don't have to trawl our cmake to find them.

https://github.com/llvm/llvm-project/pull/86288