Remove auxiliary macros in favor of asm_cfg stabilized in 1.93 (#5)

Author: oxalica

.github/workflows/ci.yaml

@@ -151,7 +151,8 @@ jobs:
     if: github.event.schedule != '33 20 * * *'
     steps:
       - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@1.87
+      # NB. Sync with Cargo.toml!
+      - uses: dtolnay/rust-toolchain@1.93
       - uses: Swatinem/rust-cache@v2
       - name: Test
         run: |