Add <sys/quota.h>.

It turns out that at least the Nexus 9 kernel is built without CONFIG_QUOTA.
If we decide we're going to mandate quota functionality, I'm happy for us to
be a part of CTS that ensures that happens, but I don't want to be first, so
there's not much to test here other than "will it compile?". The strace
output looks right though.

Bug: http://b/27948821
Bug: http://b/27952303
Change-Id: If667195eee849ed17c8fa9110f6b02907fc8fc04
diff --git a/libc/arch-x86/syscalls/quotactl.S b/libc/arch-x86/syscalls/quotactl.S
new file mode 100644
index 0000000..326cf87
--- /dev/null
+++ b/libc/arch-x86/syscalls/quotactl.S
@@ -0,0 +1,44 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(quotactl)
+    pushl   %ebx
+    .cfi_def_cfa_offset 8
+    .cfi_rel_offset ebx, 0
+    pushl   %ecx
+    .cfi_adjust_cfa_offset 4
+    .cfi_rel_offset ecx, 0
+    pushl   %edx
+    .cfi_adjust_cfa_offset 4
+    .cfi_rel_offset edx, 0
+    pushl   %esi
+    .cfi_adjust_cfa_offset 4
+    .cfi_rel_offset esi, 0
+
+    call    __kernel_syscall
+    pushl   %eax
+    .cfi_adjust_cfa_offset 4
+    .cfi_rel_offset eax, 0
+
+    mov     24(%esp), %ebx
+    mov     28(%esp), %ecx
+    mov     32(%esp), %edx
+    mov     36(%esp), %esi
+    movl    $__NR_quotactl, %eax
+    call    *(%esp)
+    addl    $4, %esp
+
+    cmpl    $-MAX_ERRNO, %eax
+    jb      1f
+    negl    %eax
+    pushl   %eax
+    call    __set_errno_internal
+    addl    $4, %esp
+1:
+    popl    %esi
+    popl    %edx
+    popl    %ecx
+    popl    %ebx
+    ret
+END(quotactl)