j: add support for armv[67]* and i686* archs
j: add support for armv[67]* and i686* archs

The primary change here is to remove the previous restrictions on `arch`.
To accomplish this, several tweaks were needed to coax the upstream
build scripts to behave more reasonably.

These changes also uncovered the fact that the scripts were not
respecting the CFLAGS and LDFLAGS of the environment. This commit also
fixes that.

For details about the specific changes to upstream we introduce, see the
accompanying comments in the template.

necrophcodr/void-packages,necrophcodr/void-packages,necrophcodr/void-packages,necrophcodr/void-packages,necrophcodr/void-packages