Add definitions for riscv64gc-unknown-fuchsia

Cargo.lock

@@ -2933,9 +2933,9 @@ checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
 [[package]]
 name = "libc"
-version = "0.2.140"
+version = "0.2.142"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "99227334921fae1a979cf0bfdfcc6b3e5ce376ef57e16fb6fb3ea2ed6095f80c"
+checksum = "6a987beff54b60ffa6d51982e1aa1146bc42f19bd26be28b0586f252fccf5317"
 dependencies = [
  "rustc-std-workspace-core",
 ]

library/core/src/ffi/mod.rs

@@ -143,7 +143,10 @@ mod c_char_definition {
                     target_arch = "powerpc"
                 )
             ),
-            all(target_os = "fuchsia", target_arch = "aarch64"),
+            all(
+                target_os = "fuchsia",
+                any(target_arch = "aarch64", target_arch = "riscv64")
+            ),
             all(target_os = "nto", target_arch = "aarch64"),
             target_os = "horizon"
         ))] {

library/std/Cargo.toml

@@ -15,7 +15,7 @@ cfg-if = { version = "1.0", features = ['rustc-dep-of-std'] }
 panic_unwind = { path = "../panic_unwind", optional = true }
 panic_abort = { path = "../panic_abort" }
 core = { path = "../core" }
-libc = { version = "0.2.140", default-features = false, features = ['rustc-dep-of-std'] }
+libc = { version = "0.2.142", default-features = false, features = ['rustc-dep-of-std'] }
 compiler_builtins = { version = "0.1.91" }
 profiler_builtins = { path = "../profiler_builtins", optional = true }
 unwind = { path = "../unwind" }

library/std/src/os/fuchsia/raw.rs

@@ -286,3 +286,9 @@ pub struct stat {
         pub __unused: [c_long; 3],
     }
 }
+
+#[cfg(target_arch = "riscv64")]
+mod arch {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub use libc::{blkcnt_t, blksize_t, ino_t, nlink_t, off_t, stat, time_t};
+}