[meson] Update subset tests list from autotools

diff --git a/test/subset/meson.build b/test/subset/meson.build
index a75b8f7..525cd89 100644
--- a/test/subset/meson.build
+++ b/test/subset/meson.build
@@ -10,9 +10,13 @@
   'layout.gpos3',
   'layout.gpos4',
   'layout.gpos6',
+  'layout.gpos8',
   'layout.gsub3',
   'layout.gsub6',
   'layout.gdef',
+  'layout.context',
+  'layout.gdef-varstore',
+  'layout.gdef-attachlist',
   'cmap',
   'cmap14',
   'sbix',