vendor riscv64 sys.rs (#324)

Tested on a riscv64 device with io-uring-test.

Author: Xeonacid

.github/workflows/ci.yml

@@ -47,6 +47,7 @@ jobs:
           - x86_64-unknown-linux-gnu
           - x86_64-unknown-linux-musl
           - aarch64-unknown-linux-gnu
+          - riscv64gc-unknown-linux-gnu
 
     steps:
       - uses: actions/checkout@v4

src/sys/mod.rs

@@ -17,7 +17,11 @@ use libc::*;
 
 #[cfg(all(
     not(feature = "bindgen"),
-    not(any(target_arch = "x86_64", target_arch = "aarch64")),
+    not(any(
+        target_arch = "x86_64",
+        target_arch = "aarch64",
+        target_arch = "riscv64"
+    )),
     not(io_uring_skip_arch_check)
 ))]
 compile_error!(