test: disable recover4 test to fix ppc64 builds

Updates #10180

Temporarily disable this test on ppc64 systems as all our builders use 64k page size.

We need a portable way to get the page size of the host so we can correctly size the mmap hole.

Change-Id: Ibd36ebe2f54cf75a44667e2070c385f0daaca481
Reviewed-on: https://go-review.googlesource.com/7652
Reviewed-by: Andrew Gerrand <adg@golang.org>
diff --git a/test/recover4.go b/test/recover4.go
index 115d5a0..5f66a50 100644
--- a/test/recover4.go
+++ b/test/recover4.go
@@ -1,4 +1,5 @@
 // +build linux darwin
+// +build !ppc64,!ppc64le
 // run
 
 // Copyright 2015 The Go Authors.  All rights reserved.