illumos gate

We can take the opportunity to update to GCC 7.5.0 instead of 7.4, and also pull in a couple more patches from Andy. This now basically has us level with both illumos-extra from Joyent and OmniOS's GCC. pkgsrc and OI are an unknown state at this point.

The tree is here:

https://github.com/joyent/gcc/tree/il-7_5_0

I ran the test suite, and compared it to a GCC 7.4-il1 run:

https://us-east.manta.joyent.com//jlevon/public/gcc/gcc-7.5.0-il-1/mail-report.diff

which afaict, looks good, or at least as good as 7.4

Full results are:

https://us-east.manta.joyent.com/jlevon/public/gcc/gcc-7.5.0-il-1/check.out

Note: the only patch changes were the two new ones at the top of the stack

So far I've built an illumos-gate with this compiler, and booted a test system for running util-tests, os-tests, elf-tests, and crypto-tests. I also built SmartOS with the compiler and ran it on a headnode with some basic smoke testing.

DTrace+CTF testing underway.

I compared against oi-userland's 7.5.0. Aside from Andy's two most recent patches, they also have:

https://github.com/OpenIndiana/oi-userland/blob/oi/hipster/components/developer/gcc-7/patches/1001-values.patch

That's something we should probably look at bringing in later; I don't think it's needed right now.

A SmartOS ctf diff all comparison:

https://us-east.manta.joyent.com//jlevon/public/gcc/gcc-7.5.0-il-1/ctf-versus-7.4-build.diff

just a little bit of noise.

I ran the DTrace test suite without any failures attributable to the gcc change.