[test] Skip webkit test too slow for ppc.

test/webkit/webkit.status

Index: test/webkit/webkit.status
diff --git a/test/webkit/webkit.status b/test/webkit/webkit.status
index 1c0f40ffff6a0fdc11e4ec3597360bfc8ba8d4a8..52a15965ae6c0bf5bf60e5c7e160bf3314801a9d 100644
--- a/test/webkit/webkit.status
+++ b/test/webkit/webkit.status
@@ -66,6 +66,10 @@
   # Too slow for mips big-endian boards on bots (no FPU).
   'dfg-int-overflow-in-loop': [SKIP],
 }], # 'arch == mips'
+['arch == ppc or arch == ppc64', {
+  # Too slow.
+  'dfg-int-overflow-in-loop': [SKIP],
+}], # 'arch == ppc or arch == ppc64'
 
 ##############################################################################
 ['asan == True', {