sanitizer macro: request for comments

[cc: people who contributed sanitizer-related changes to configure.ac in
sudo, systemd and NetworkManager]

Hey,

I wrote an m4 macro (attached to this email) for enabling sanitizers, e.g.
AddressSanitizer, MemorySanitizer, UndefinedSanitizer, also known as ASAN,
MSAN and UBSAN, respectively, see also https://github.com/google/sanitizers
for more details.

I decided to write a macro because I saw ad-hoc configure code to that
effect in at least systemd, sudo and NetworkManager, so I figured
centralizing that code into AX_SANITIZERS might make sense. Do you agree
with that assessment, or is there anything that would prevent you from
using AX_SANITIZERS in your project?

There are two open questions with the macro, though:

• Please see the TODO in the code about having to specify -Wc, for libtool
— any pointers/insights as to how to approach that?

• Please see the TODO in the code about specifying -O1 — does that make
sense? Any ideas about how to accomplish that?

Thanks for any feedback!

-- 
Best regards,
Michael