Makefile: re-wordsmith the blurb about xtoolchain ports

[kevans]

Summary

The new version only includes a specific version once, and uses that that's currently advised by tinderbox: -gcc6.

It also advises just installing the pkg, but mentions in a side-note at the end where to find the source in the ports tree.

[jrtc27]

Seems good to me, though maybe N would be better than X to avoid confusion with the X in xtoolchain leading people to think gccX means a cross GCC if they don't bother looking too closely at the example? That or change "xtoolchain" to "cross toolchain" ("cross-toolchain"?), which also nicely matches CROSS_TOOLCHAIN.

[kevans]

In D26820#597869, @jrtc27 wrote:

Seems good to me, though maybe N would be better than X to avoid confusion with the X in xtoolchain leading people to think gccX means a cross GCC if they don't bother looking too closely at the example? That or change "xtoolchain" to "cross toolchain" ("cross-toolchain"?), which also nicely matches CROSS_TOOLCHAIN.

I'm tempted to do both, in case someone tries to make the logical leap from cross -> X anyways. Writing 'xtoolchain' was kind of just habit from the old ports that should be retired, and we probably shouldn't accidentally draw someone towards those ones.

[jhb]

+1 to the X -> N and xtoolchain -> "cross toolchain" changes.

Makefile

100

[kevans]

Incorporate feedback

[jrtc27]

One minor change but otherwise 👍.

Makefile

93

[kevans]

Makefile

93

I will fix this one pre-commit, thanks :)