Adds support for m1 chips

[imajes]

Integrates apple silicon into the build process, removing some older build targets (ppc, 32 bit).

[imajes]

Similar to #88 -- i ended up doing this work and only saw #88 as I was getting ready to submit the PR req... nice job @kevintom :)

in this case, it just builds a universal binary if it's on an arm64 system, but falls back to current behavior if not.

[kevintom]

thanks @imajes

i actually initially tried this approach as well, passing both architectures to the compiler

the only problem was that then the binary is tied to the same SDK version and since M1 support only exists on versions 11+ it kind of cuts off anyone running older versions on Intel systems with this binary.

that's when I started looking for ways to create a universal binary that would allow support for older versions of the SDK on Intel but also let us set the SDK target to the current version for M1 support.

[imajes]

@kevintom yeah, i wasn't sure how well it'd work pre 11x. I wondered if pulled in an older SDK would that be sufficient?

either way, the lipo step is still doing the same, but I guess you're using the original build vs building both at the same time. It feels like that's a bit risky, but.. 🤷

if the lipo step is the way, then in your PR it would make sense to do a rake step to do those bits.

[thibaudgg]

@imajes closing that one as I went with the @kevintom #88 PR, does that work for you? Thanks for your work!