lang/zig: force baseline instead of native compilation

[dch]

Summary

Systems that don't have AVX2 or newer CPU instructions will crash
with SIGILL. Using baseline zig target should address this but
make zig slower everywhere for everyone.

PR: 269206

[dch]

use suggested trick from irc zig channel

[dch]

without typo

[dch]

and more typos

[diizzy]

According to https://github.com/ziglang/zig/blob/master/CMakeLists.txt#L115 ZIG_TARGET_MCPU also gets used for compiler switch -mcpu= so what you could possibly do is mapping it to ${CPUTYPE} (https://cgit.freebsd.org/src/tree/share/examples/etc/make.conf?h=releng/13.1#n56) if its undefined.
Is mcpu/mtune=baseline defined anywhere? I found option generic documented but that seems like it's going to change between compiler versions.

[jbeich]

Does this obsolete -Dcpu=${CPUTYPE:Ubaseline} in consumers like x11-wm/river?

[jbeich]

lang/zig/Makefile

31

How CMAKE_FLAGS is passed to the build script? USES=cmake has CMAKE_ARGS but not CMAKE_FLAGS.

Also, the type can be annotated e.g., -DZIG_TARGET_MCPU:STRING=baseline.

[dch]

amend flags after IRC convo with zig devs and ok from zig users

[dch]

the --verbose addition allows seeing after the build, in the logs, what tuples were chosen.

lang/zig/Makefile

31

this has since been fixed locally but not pushed up to phab. I'm not familiar with type annotations but
apparently clang or cmake can infer a string. I'll roll with whatever's done in general in ports.