library/std: raw: Add support for RISC-V 32-bit

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Author: alistair23

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

@@ -22,7 +22,8 @@ mod tests;
             target_arch = "powerpc",
             target_arch = "powerpc64",
             target_arch = "s390x",
-            target_arch = "riscv64"
+            target_arch = "riscv64",
+            target_arch = "riscv32"
         )
     ),
     all(target_os = "android", any(target_arch = "aarch64", target_arch = "arm")),
@@ -65,7 +66,8 @@ pub type c_char = u8;
             target_arch = "powerpc",
             target_arch = "powerpc64",
             target_arch = "s390x",
-            target_arch = "riscv64"
+            target_arch = "riscv64",
+            target_arch = "riscv32"
         )
     ),
     all(target_os = "android", any(target_arch = "aarch64", target_arch = "arm")),