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-mips/syscalls/fstat64.S b/libc/arch-mips/syscalls/fstat64.S
new file mode 100644
index 0000000..de09df5
--- /dev/null
+++ b/libc/arch-mips/syscalls/fstat64.S
@@ -0,0 +1,26 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <asm/unistd.h>
+    .text
+    .globl fstat64
+    .align 4
+    .ent fstat64
+
+fstat64:
+    .set noreorder
+    .cpload $t9
+    li $v0, __NR_fstat64
+    syscall
+    bnez $a3, 1f
+    move $a0, $v0
+    j $ra
+    nop
+1:
+    la $t9,__set_errno
+    j $t9
+    nop
+    .set reorder
+    .end fstat64
+
+    .globl _C_LABEL(fstat)
+    .equ _C_LABEL(fstat), _C_LABEL(fstat64)