build: enable support for aix/ppc64

* Adds "aix/ppc64" to the cross-compile target list.
* Including AIX in the build tag of "metadata_other.go".
* Excluding AIX from the main ncdu build tags.
* Marking AIX as an unsupported platform for ncdu.
* Excluding AIX from the fallback redirect implementation.
* Excluding AIX from unix build tags to avoid undefined unix.WNOHANG.

backend/local/metadata_other.go

@@ -1,4 +1,4 @@
-//go:build dragonfly || plan9 || js
+//go:build dragonfly || plan9 || js || aix
 
 package local
 

bin/cross-compile.go

@@ -74,6 +74,7 @@ var osarches = []string{
 	"plan9/amd64",
 	"solaris/amd64",
 	// "js/wasm", // Rclone is too big for js/wasm until https://github.com/golang/go/issues/64856 is fixed
+    "aix/ppc64",
 }
 
 // Special environment flags for a given arch

cmd/ncdu/ncdu.go

@@ -1,4 +1,4 @@
-//go:build !plan9 && !js
+//go:build !plan9 && !js && !aix
 
 // Package ncdu implements a text based user interface for exploring a remote
 package ncdu

cmd/ncdu/ncdu_unsupported.go

@@ -1,7 +1,7 @@
 // Build for ncdu for unsupported platforms to stop go complaining
 // about "no buildable Go source files "
 
-//go:build plan9 || js
+//go:build plan9 || js || aix
 
 // Package ncdu implements a text based user interface for exploring a remote
 package ncdu

fs/log/redirect_stderr.go

@@ -1,6 +1,6 @@
 // Log the panic to the log file - for oses which can't do this
 
-//go:build !windows && !darwin && !dragonfly && !freebsd && !linux && !nacl && !netbsd && !openbsd
+//go:build !windows && !darwin && !dragonfly && !freebsd && !linux && !nacl && !netbsd && !openbsd && !aix
 
 package log
 

lib/daemonize/daemon_other.go

@@ -1,4 +1,4 @@
-//go:build !unix
+//go:build !unix || aix
 
 // Package daemonize provides daemonization stub for non-Unix platforms.
 package daemonize

lib/daemonize/daemon_unix.go

@@ -1,4 +1,4 @@
-//go:build unix
+//go:build unix && !aix
 
 // Package daemonize provides daemonization interface for Unix platforms.
 package daemonize