apkbuild-cpan: XS modules using Module::Build now obtain Perl CFLAGS properly.

apkbuild-cpan.in

@@ -174,6 +174,7 @@ EOF
 		$build_func = <<'EOF';
 build() {
 	cd "$_builddir"
+        export CFLAGS=`perl -MConfig -E 'say $Config{ccflags}'`
 	./Build && ./Build test
 }
 EOF