unix: remove StTimespec type on AIX

On AIX, Stat_t's fields dealing with time are of type StTimespec while
all other GOOS are using Timespec.
StTimespec and Timespec are the same on ppc but not in ppc64. Therefore,
values returned by ppc64 syscalls need to be adjusted in order to
allow the use of Timespec instead of StTimespec.

Fixes golang/go#32073

Change-Id: I0c212bf1741a27c49e995bf928d4941b6d583e54
Reviewed-on: https://go-review.googlesource.com/c/sys/+/177838
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/unix/zsyscall_aix_ppc.go b/unix/zsyscall_aix_ppc.go
index 4a9e99a..ed657ff 100644
--- a/unix/zsyscall_aix_ppc.go
+++ b/unix/zsyscall_aix_ppc.go
@@ -859,7 +859,7 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Fstat(fd int, stat *Stat_t) (err error) {
+func fstat(fd int, stat *Stat_t) (err error) {
 	r0, er := C.fstat(C.int(fd), C.uintptr_t(uintptr(unsafe.Pointer(stat))))
 	if r0 == -1 && er != nil {
 		err = er
@@ -869,7 +869,7 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Fstatat(dirfd int, path string, stat *Stat_t, flags int) (err error) {
+func fstatat(dirfd int, path string, stat *Stat_t, flags int) (err error) {
 	_p0 := uintptr(unsafe.Pointer(C.CString(path)))
 	r0, er := C.fstatat(C.int(dirfd), C.uintptr_t(_p0), C.uintptr_t(uintptr(unsafe.Pointer(stat))), C.int(flags))
 	if r0 == -1 && er != nil {
@@ -953,7 +953,7 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Lstat(path string, stat *Stat_t) (err error) {
+func lstat(path string, stat *Stat_t) (err error) {
 	_p0 := uintptr(unsafe.Pointer(C.CString(path)))
 	r0, er := C.lstat(C.uintptr_t(_p0), C.uintptr_t(uintptr(unsafe.Pointer(stat))))
 	if r0 == -1 && er != nil {
@@ -1071,9 +1071,9 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Stat(path string, stat *Stat_t) (err error) {
+func stat(path string, statptr *Stat_t) (err error) {
 	_p0 := uintptr(unsafe.Pointer(C.CString(path)))
-	r0, er := C.stat(C.uintptr_t(_p0), C.uintptr_t(uintptr(unsafe.Pointer(stat))))
+	r0, er := C.stat(C.uintptr_t(_p0), C.uintptr_t(uintptr(unsafe.Pointer(statptr))))
 	if r0 == -1 && er != nil {
 		err = er
 	}