[libc-commits] [libc] [libc] Add posix_memalign as external entrypoint on Linux x86/ARM. (PR #185310)

[Alexey Samsonov via libc-commits]

vonosmas wrote:

> What happens if someone does not declare the scudo allocator on the cmake invocation?

After this change, the generated `<stdlib.h>` header on Linux will have a `posix_memalign` declaration (it doesn't have it now). If the `LLVM_LIBC_INCLUDE_SCUDO` was not specified, then `libc.a` will not have any memory allocation functions (`malloc`, `free`, `posix_memalign`, etc.), and the user will need to provide their own allocator. 

https://github.com/llvm/llvm-project/pull/185310