Fix misc-include-cleaner warnings from clang-tidy

Change-Id: Ica7bbfb1415c93a265d9ec49691bcbb93f2062d1
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/190280
Commit-Queue: James Price <jrprice@google.com>
Reviewed-by: James Price <jrprice@google.com>
Auto-Submit: David Neto <dneto@google.com>
diff --git a/src/tint/lang/msl/writer/raise/module_scope_vars_test.cc b/src/tint/lang/msl/writer/raise/module_scope_vars_test.cc
index cf3fe76..2892d60 100644
--- a/src/tint/lang/msl/writer/raise/module_scope_vars_test.cc
+++ b/src/tint/lang/msl/writer/raise/module_scope_vars_test.cc
@@ -29,6 +29,7 @@
 
 #include <utility>
 
+#include "src/tint/lang/core/fluent_types.h"
 #include "src/tint/lang/core/ir/transform/helper_test.h"
 #include "src/tint/lang/core/type/sampled_texture.h"