unix: fix epoll and missing syscalls for ppc64x

The epoll_event struct was not correct for ppc64* arches. This has
been fixed in the syscall package by CL 22207. This patch makes
the same change, in addition to adding some missing syscalls needed
by fsnotify.

See the following for more info:
https://github.com/fsnotify/fsnotify/issues/130
https://github.com/golang/go/issues/15393

Fixes #15393

Change-Id: Iedad28274ec1d3e48787c34991a725690f3b204d
Signed-off-by: Christy Perez <christy@linux.vnet.ibm.com>
Reviewed-on: https://go-review.googlesource.com/22605
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/unix/ztypes_linux_ppc64le.go b/unix/ztypes_linux_ppc64le.go
index f7c8451..8e25c9f 100644
--- a/unix/ztypes_linux_ppc64le.go
+++ b/unix/ztypes_linux_ppc64le.go
@@ -589,9 +589,10 @@
 }
 
 type EpollEvent struct {
-	Events uint32
-	Fd     int32
-	Pad    int32
+	Events  uint32
+	X_padFd int32
+	Fd      int32
+	Pad     int32
 }
 
 const (