git: 2487e484e75a - main - Uses/cargo: Mirror _RUST_ARCH_* mapping from lang/rust

The branch main has been updated by tobik:

URL: https://cgit.FreeBSD.org/ports/commit/?id=2487e484e75a45b72964e189d2654720c0b34dd0

commit 2487e484e75a45b72964e189d2654720c0b34dd0
Author:     Tobias Kortkamp <tobik@FreeBSD.org>
AuthorDate: 2021-11-07 14:15:07 +0000
Commit:     Tobias Kortkamp <tobik@FreeBSD.org>
CommitDate: 2021-11-07 15:24:13 +0000

    Uses/cargo: Mirror _RUST_ARCH_* mapping from lang/rust
---
 Mk/Uses/cargo.mk | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Mk/Uses/cargo.mk b/Mk/Uses/cargo.mk
index 1da833d29c4f..89e0d0704013 100644
--- a/Mk/Uses/cargo.mk
+++ b/Mk/Uses/cargo.mk
@@ -109,7 +109,10 @@ RUSTDOC?=	${LOCALBASE}/bin/rustdoc
 CARGO_TARGET_DIR?=	${WRKDIR}/target
 
 # Default target platform (affects some RUSTFLAGS if passed)
-CARGO_BUILD_TARGET?=	${ARCH:S/amd64/x86_64/:S/i386/i686/}-unknown-${OPSYS:tl}
+CARGO_BUILD_TARGET?=	${_CARGO_RUST_ARCH_${ARCH}:U${ARCH}}-unknown-${OPSYS:tl}
+
+_CARGO_RUST_ARCH_amd64=		x86_64
+_CARGO_RUST_ARCH_i386=		i686
 
 # Environment for cargo
 #  - CARGO_HOME: local cache of the registry index