Simplify close(2) EINTR handling.

This doesn't affect code like Chrome that correctly ignores EINTR on
close, makes code that tries TEMP_FAILURE_RETRY work (where before it might
have closed a different fd and appeared to succeed, or had a bogus EBADF),
and makes "goto fail" code work (instead of mistakenly assuming that EINTR
means that the close failed).

Who loses? Anyone actively trying to detect that they caught a signal while
in close(2). I don't think those people exist, and I think they have better
alternatives available.

Bug: https://code.google.com/p/chromium/issues/detail?id=269623
Bug: http://b/20501816
Change-Id: I11e2f66532fe5d1b0082b2433212e24bdda8219b
diff --git a/libc/arch-arm64/syscalls/___close.S b/libc/arch-arm64/syscalls/___close.S
new file mode 100644
index 0000000..8fb8361
--- /dev/null
+++ b/libc/arch-arm64/syscalls/___close.S
@@ -0,0 +1,15 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(___close)
+    mov     x8, __NR_close
+    svc     #0
+
+    cmn     x0, #(MAX_ERRNO + 1)
+    cneg    x0, x0, hi
+    b.hi    __set_errno_internal
+
+    ret
+END(___close)
+.hidden ___close