meson: generate shader headers

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

ui/shader/meson.build

@@ -0,0 +1,15 @@
+shaders = [
+  ['texture-blit', 'frag'],
+  ['texture-blit', 'vert'],
+  ['texture-blit-flip', 'vert'],
+]
+
+foreach e : shaders
+  output = '@0@-@1@.h'.format(e[0], e[1])
+  genh += custom_target(output,
+                output: output,
+                capture: true,
+                build_by_default: true, # to be removed when added to a target
+                input: files('@0@.@1@'.format(e[0], e[1])),
+                command: [shaderinclude, '@INPUT0@'])
+endforeach