build: Don't use -O0 which is not portable.
* src/Makefile.am (mkheader): Remove -O0 option.
- Signed-off-by: NIIBE Yutaka <firstname.lastname@example.org>
The particular part of mkheader compilation with -O0 was introduced by dkg for cross build support.
I believe that -O<number> (where <number> is not zero) is common but -O<something-other> is dependent.
Requesting non-optimization by -O0 seems GCC specific.
(I grep-ped autoconf-archive and observed the use cases of -O0.)
If we really want to support -O0 here, it would be best to add checking by:
test "$GCC" = "yes"
in configure and only add -O0 when it's gcc.
I checked libgcrypt. -O0 is used in random/Makefile.am for o_flag_munging to disable optimization for rndjent.c. For Solaris, we can skip that by --disable-O-flag-munging.