[Module::Build] order of extra_compile_flags in compile_c

[R. B. <ro...@pa...>]

I recently used Module::Build in my first CPAN project
(Device:Cdio). This is a OO Perl wrapper for my libcdio library and I
used SWIG to help me. (See ticket 17666 on rt.cpan.org; and many
thanksfor considering as an inclusion this after the next M:B
release.)

One thing that came up in this endeavor was the order or the C flags
in the compilation (compile_c).  It is helpful to turn off some gcc
warning messages until such time SWIG is fixed to not cause gcc to
emit them. So I changed the order of applying user cflags
(extra_compiler_flags) to come *after* the cflags that are picked up
as part of the Perl configuration (via Config). Another possibility is
to add a new option to allow cflags specified before *and* afterwards.

(If this is something I should add a ticket for in rt.cpan.org, let me
know.)

Thanks.