Implement some of the missing LFS64 support.

This gives us:

* <dirent.h>
  struct dirent64
  readdir64, readdir64_r, alphasort64, scandir64

* <fcntl.h>
  creat64, openat64, open64.

* <sys/stat.h>
  struct stat64
  fstat64, fstatat64, lstat64, stat64.

* <sys/statvfs.h>
  struct statvfs64
  statvfs64, fstatvfs64.

* <sys/vfs.h>
  struct statfs64
  statfs64, fstatfs64.

This also removes some of the incorrect #define hacks we've had in the
past (for stat64, for example, which we promised to clean up way back
in bug 8472078).

Bug: 11865851
Bug: 8472078
Change-Id: Ia46443521918519f2dfa64d4621027dfd13ac566
diff --git a/libc/arch-mips64/syscalls/statfs64.S b/libc/arch-mips64/syscalls/statfs64.S
new file mode 100644
index 0000000..2fd7603
--- /dev/null
+++ b/libc/arch-mips64/syscalls/statfs64.S
@@ -0,0 +1,34 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <asm/unistd.h>
+#include <machine/asm.h>
+#include <machine/regdef.h>
+    .text
+    .globl statfs64
+    .align 4
+    .ent statfs64
+
+statfs64:
+    .set push
+    .set noreorder
+    li v0, __NR_statfs
+    syscall
+    bnez a3, 1f
+    move a0, v0
+    j ra
+    nop
+1:
+    move t0, ra
+    bal     2f
+    nop
+2:
+    .cpsetup ra, t1, 2b
+    LA t9,__set_errno
+    .cpreturn
+    j t9
+    move ra, t0
+    .set pop
+    .end statfs64
+
+    .globl _C_LABEL(statfs)
+    .equ _C_LABEL(statfs), _C_LABEL(statfs64)