perl-module.eclass: don't set 'ccflags' for Module::Build

TL;DR: If we set 'ccflags', we're clobbering the Perl default. We're already
setting 'optimize' which is what we're supposed to use here.

We set ccflags *and* optimize for Module::Build (which dev-perl/Net-DNS uses),
while we only set OPTIMIZE (case is fine) for MM (which dev-perl/Net-LibIDN2 uses).

ccflags clobbers the Perl default, while optimize appends. We should just set optimize -
to not clobber what Perl sets, but also for consistency between the two build systems).

(Unfortunately, this does mean we also inherit things we don't really
want to, which don't affect ABI, like -fno-strict-aliasing, but let's
live with it for now...)

Bug: https://bugs.gentoo.org/261375
Bug: https://bugs.gentoo.org/877659
Closes: https://bugs.gentoo.org/932176
Signed-off-by: Sam James <sam@gentoo.org>

eclass/perl-module.eclass

@@ -279,7 +279,6 @@ perl-module_src_configure() {
 			--config ld="$(tc-getCC)" \
 			--config nm="$(tc-getNM)" \
 			--config ranlib="$(tc-getRANLIB)" \
-			--config ccflags="${CFLAGS}" \
 			--config optimize="${CFLAGS}" \
 			--config ldflags="${LDFLAGS}" \
 			"${myconf_local[@]}"