Add {get,set}domainname(2)

{get,set}domainname aren't in POSIX but are widely-implemented
extensions.

The Linux kernel provides a setdomainname syscall but not a symmetric
getdomainname syscall, since it expects userspace to get the domain name
from uname(2).

Change-Id: I96726c242f4bb646c130b361688328b0b97269a0
Signed-off-by: Greg Hackmann <ghackmann@google.com>
diff --git a/libc/arch-x86/syscalls/setdomainname.S b/libc/arch-x86/syscalls/setdomainname.S
new file mode 100644
index 0000000..57189fe
--- /dev/null
+++ b/libc/arch-x86/syscalls/setdomainname.S
@@ -0,0 +1,26 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(setdomainname)
+    pushl   %ebx
+    .cfi_def_cfa_offset 8
+    .cfi_rel_offset ebx, 0
+    pushl   %ecx
+    .cfi_adjust_cfa_offset 4
+    .cfi_rel_offset ecx, 0
+    mov     12(%esp), %ebx
+    mov     16(%esp), %ecx
+    movl    $__NR_setdomainname, %eax
+    int     $0x80
+    cmpl    $-MAX_ERRNO, %eax
+    jb      1f
+    negl    %eax
+    pushl   %eax
+    call    __set_errno_internal
+    addl    $4, %esp
+1:
+    popl    %ecx
+    popl    %ebx
+    ret
+END(setdomainname)