Testing linker issue on windows (Use linkme to collect starlark globals)

Summary: I need to add more starlark globals in crates which buck2_interpreter_for_build does not depend on, and while LateBinding works, it requires more work.

New idea is to use linkme.

We already use linkme to

collect types of command line args

https://www.internalfb.com/code/fbsource/[a60e45a76980bdb5849c16b1c57e23bdefef0b9a]/fbcode/buck2/app/buck2_build_api/src/interpreter/rule_defs/cmd_args/command_line_arg_like_type.rs?lines=39-40

collect env variables for buck2 help-env

https://www.internalfb.com/code/fbsource/[a60e45a76980bdb5849c16b1c57e23bdefef0b9a]/fbcode/buck2/app/buck2_core/src/env/registry.rs?lines=26-27

That would be third. It is

more risky than previous two considered our previous fight with #[ctor] (which resulted in introduction of LateBinding
if it won't work, diagnostics will be bad
and it increases the amount of hidden magic

so I'm not 100% sure. But how much cleaner code is now!

Empty

init_late_bindings() {}

are kept to avoid triggering various tools from linters to linkers, who may start removing dependencies.

Differential Revision: D56078261

facebook / buck2

Testing linker issue on windows (Use linkme to collect starlark globals) #620