[llvm-branch-commits] [libcxx] [libcxxabi] [llvm] release/21.x: [libc++][hardening] Introduce assertion semantics. (#149459) (PR #151095)

[Konstantin Varlamov via llvm-branch-commits]

var-const wrote:

Reason for cherry-picking: this patch is a follow-up to https://github.com/llvm/llvm-project/pull/150481 and the same rationale applies: we want to gain real-world experience with this under the experimental flag to allow us to roll this out in the next release.

https://github.com/llvm/llvm-project/pull/151095