meson: Don't build glsl cache_test when shader cache is disabled

v2: - Use new with_shader_cache variable instead of
      host_machine.system() == 'windows'

Reviewed-by: Eric Anholt <eric@anholt.net>

src/compiler/glsl/tests/meson.build

@@ -30,19 +30,20 @@ test(
   suite : ['compiler', 'glsl'],
 )
 
-test(
+if with_shader_cache
-  'cache_test',
+  test(
-  executable(
     'cache_test',
-    'cache_test.c',
+    executable(
-    c_args : [c_vis_args, c_msvc_compat_args, no_override_init_args],
+      'cache_test',
-    include_directories : [inc_common, inc_glsl],
+      'cache_test.c',
-    link_with : [libglsl],
+      c_args : [c_vis_args, c_msvc_compat_args, no_override_init_args],
-    dependencies : [dep_clock, dep_thread],
+      include_directories : [inc_common, inc_glsl],
-  ),
+      link_with : [libglsl],
-  suite : ['compiler', 'glsl'],
+      dependencies : [dep_clock, dep_thread],
-)
+    ),
-
+    suite : ['compiler', 'glsl'],
+  )
+endif
 
 test(
   'general_ir_test',