Renamed WIN64 to WIN_64

[braw-lee]

Fixes issue #2768

gcc/rust/ChangeLog:

* backend/rust-compile-base.cc (HIRCompileBase::setup_abi_options): Renamed `WIN64` to `WIN_64`
* util/rust-abi.cc (get_abi_from_string): Likewise
(get_string_from_abi): Likewise
* util/rust-abi.h (enum ABI): Likewise

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[braw-lee]

resolves #2768
Sorry for the force-commits, they are nothing but me trying to satisfy the GNU commit format checker.
Let me know if the PR is acceptable or not (this is my first PR to Rust-GCC)
@CohenArthur

[dkm]

Hello @braw-lee !
Thanks for your contribution! Have you read https://gcc.gnu.org/dco.html? We would need a simple message that clearly states you've read and acknowledge it.

[P-E-P]

resolves #2768 Sorry for the force-commits, they are nothing but me trying to satisfy the GNU commit format checker. Let me know if the PR is acceptable or not (this is my first PR to Rust-GCC)

Don't worry about force pushes on your own branches, most people force push and rewrite their history a lot

[braw-lee]

Hello @braw-lee ! Thanks for your contribution! Have you read https://gcc.gnu.org/dco.html? We would need a simple message that clearly states you've read and acknowledge it.

Yes, I have read and acknowledged https://gcc.gnu.org/dco.html

[philberty]

LGTM