build: integrate new cross toolchains w/ Bazel

[rickystewart]

1. Add new toolchains that run on ARM hosts.
2. Add new toolchains that target M1 Mac's.

Release note: None

Jira issue: CRDB-14852

[cockroach-teamcity]

This change is 

[mari-crl]

Nice work! :D Woohoo, ARM builds!!

Reviewed 12 of 12 files at r1, all commit messages.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @rickystewart)

---

build/toolchains/crosstool-ng/toolchain.bzl, line 4 at r1 (raw file):

    if rctx.attr.host == "x86_64":
        url = "https://storage.googleapis.com/public-bazel-artifacts/toolchains/crosstool-ng/{}/20220317-191459/{}.tar.gz".format(rctx.attr.host, rctx.attr.target)
    elif rctx.attr.host == "aarch64":

Just for my curiosity's sake, why the different URL for aarch64? Not supported in the most recent release yet?

---

c-deps/BUILD.bazel, line 17 at r1 (raw file):

        "@io_bazel_rules_go//go/platform:darwin_arm64": [
            "--host=aarch64-apple-darwin21.2",
            "--with-lg-page=16",

Hmmm, why do we need this for arm and not for anything else?

---

c-deps/BUILD.bazel, line 186 at r1 (raw file):

        "//build/toolchains:cross": {
            "AUTOM4TE": "$(execpath :autom4te)",
            "krb5_cv_attr_constructor_destructor": "yes",

Why the changes here?

[mari-crl]

Oop, didn't hit approve.

Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @rickystewart)

[rickystewart]

Just for my curiosity's sake, why the different URL for aarch64? Not supported in the most recent release yet?

To build these toolchains I ran the CI script twice, once on a normal x86_64 agent and once on an ARM agent. The script is written to use the value of date +%Y%m%d-%H%M%S for the URL the toolchains are uploaded to, and so they'll write to different URL's as a matter of course (they'll never initiate this write at the exact same second). See https://teamcity.cockroachdb.com/buildConfiguration/Internal_Release_BuildAndPublishCrossToolchains?mode=builds#all-projects vs. https://teamcity.cockroachdb.com/buildConfiguration/Internal_Release_BuildAndPublishCrossToolchainsArmHost?mode=builds#all-projects

Hmmm, why do we need this for arm and not for anything else?

Our jemalloc has this issue when cross-compiling for macOS ARM for some reason. If I remove this line, I get this error:

cockroach$ ./artifacts/cockroach-short
<jemalloc>: Error allocating TSD for 
zsh: abort      ./artifacts/cockroach-short

Adding the line back gets rid of it.

Why the changes here?

This helps configure figure out a few checks that it otherwise can't perform when we're cross-compiling. Here's another example.

[rickystewart]

bors r=mari-crl

[craig]

Build succeeded:

• GitHub CI (Cockroach)