move os_get_random_bytes to os.zig

CMakeLists.txt

@@ -126,6 +126,7 @@ set(ZIG_STD_SRC
     "${CMAKE_SOURCE_DIR}/std/test_runner_libc.zig"
     "${CMAKE_SOURCE_DIR}/std/test_runner_nolibc.zig"
     "${CMAKE_SOURCE_DIR}/std/std.zig"
+    "${CMAKE_SOURCE_DIR}/std/os.zig"
     "${CMAKE_SOURCE_DIR}/std/syscall.zig"
     "${CMAKE_SOURCE_DIR}/std/errno.zig"
     "${CMAKE_SOURCE_DIR}/std/rand.zig"

example/guess_number/main.zig

@@ -2,6 +2,7 @@ export executable "guess_number";
 
 import "std.zig";
 import "rand.zig";
+import "os.zig";
 
 pub fn main(args: [][]u8) -> %void {
     %%stderr.print_str("Welcome to the Guess Number Game in Zig.\n");

std/os.zig

@@ -0,0 +1,17 @@
+import "syscall.zig";
+import "errno.zig";
+
+pub error SigInterrupt;
+pub error Unexpected;
+
+pub fn os_get_random_bytes(buf: []u8) -> %void {
+    const amt_got = getrandom(buf.ptr, buf.len, 0);
+    if (amt_got < 0) {
+        return switch (-amt_got) {
+            EINVAL => unreachable{},
+            EFAULT => unreachable{},
+            EINTR  => error.SigInterrupt,
+            else   => error.Unexpected,
+        }
+    }
+}

std/std.zig

@@ -160,18 +160,6 @@ pub struct InStream {
     }
 }
 
-pub fn os_get_random_bytes(buf: []u8) -> %void {
-    const amt_got = getrandom(buf.ptr, buf.len, 0);
-    if (amt_got < 0) {
-        return switch (-amt_got) {
-            EINVAL => unreachable{},
-            EFAULT => unreachable{},
-            EINTR  => error.SigInterrupt,
-            else   => error.Unexpected,
-        }
-    }
-}
-
 #attribute("cold")
 pub fn abort() -> unreachable {
     raise(SIGABRT);