[compiler-rt] [libcxxabi] [libunwind] [runtimes][PAC] Harden unwinding when possible (#138571) (PR #143230)

[Oliver Hunt via llvm-commits]

================
@@ -103,10 +104,68 @@
 #define _LIBCXXABI_DTOR_FUNC
 #endif
 
-#if __cplusplus < 201103L
----------------
ojhunt wrote:

by failing to compile we ensure there are no memory safety bugs. :D

https://github.com/llvm/llvm-project/pull/143230