Add zos support to storage/azblob (#23729)

sdk/storage/azblob/internal/shared/mmf_unix.go

@@ -1,6 +1,6 @@
-//go:build go1.18 && (linux || darwin || dragonfly || freebsd || openbsd || netbsd || solaris || aix)
+//go:build go1.18 && (linux || darwin || dragonfly || freebsd || openbsd || netbsd || solaris || aix || zos)
 // +build go1.18
-// +build linux darwin dragonfly freebsd openbsd netbsd solaris aix
+// +build linux darwin dragonfly freebsd openbsd netbsd solaris aix zos
 
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License. See License.txt in the project root for license information.