For building v8 using gn on aix_ppc64, linux_s390x and linux_ppc64.

build/config/ui.gni

Index: build/config/ui.gni
diff --git a/build/config/ui.gni b/build/config/ui.gni
index aed71b47c66896f914a50cb438e63390c155140d..85c85232150c6f30b7f9e2574a8e50fe00dc87cf 100644
--- a/build/config/ui.gni
+++ b/build/config/ui.gni
@@ -34,7 +34,7 @@ declare_args() {
   use_aura = is_win || is_linux
 
   # Whether we should use glib, a low level C utility library.
-  use_glib = is_linux
+  use_glib = is_linux && !is_power_or_z

[brettw, 2017/04/26 20:07:42]

As with the is_nacl flag, can you explain why this value affects your V8
compiles?

For this one, why does the CPU architecture affect whether glib is used? I would
expect that to be a function of the OS.

[Dirk Pranke, 2017/04/26 23:32:13]

I think this is because //base has dependencies on glib, and I'd guess that
maybe glib isn't available on their ports?

[rayb, 2017/04/27 19:29:45]

//base does have dependencies on glib. My initial assumption was also that glib
wasn't available on all of our ports. As it certainly wasn't available on the
machines I was testing on. But upon closer inspection, it might just have been
an environment issue, as since then I have managed to get hold of a pLinux 64 BE
machine with the required libraries.

So that makes me almost certain that the required ones(glib-2.0 gmodule-2.0
gobject-2.0 gthread-2.0) do indeed exist on both power and z linux. They are
just not that common, or at least they are uncommon enough for me to not have
them on the machines I was running on. 

Anyways, I will turn them back on for p/Linux and z/Linux. Again, thanks for
catching that.

 }
 
 declare_args() {