[turbofan] Add more sanity checks to representation inference.

test/unittests/compiler/node-test-utils.h

Index: test/unittests/compiler/node-test-utils.h
diff --git a/test/unittests/compiler/node-test-utils.h b/test/unittests/compiler/node-test-utils.h
index 9c0392e827f88b7034695b665820672afaa72f06..cb566ee5dfd681d1845e23b1e9323e9f13e1c559 100644
--- a/test/unittests/compiler/node-test-utils.h
+++ b/test/unittests/compiler/node-test-utils.h
@@ -382,6 +382,9 @@ Matcher<Node*> IsWord32PairSar(const Matcher<Node*>& lhs_matcher,
                                const Matcher<Node*>& rhs_matcher);
 
 Matcher<Node*> IsStackSlot();
+Matcher<Node*> IsGuard(const Matcher<Type*>& type_matcher,
+                       const Matcher<Node*>& value_matcher,
+                       const Matcher<Node*>& control_matcher);
 
 }  // namespace compiler
 }  // namespace internal