[turbofan] Fix more -Wsign-compare warnings.

test/cctest/compiler/test-run-machops.cc

Index: test/cctest/compiler/test-run-machops.cc
diff --git a/test/cctest/compiler/test-run-machops.cc b/test/cctest/compiler/test-run-machops.cc
index ccf4b847697c49b9a1dd4c229b5b3a6c318a1f2a..2794aec51e505aeb02e376a290be3534766d1315 100644
--- a/test/cctest/compiler/test-run-machops.cc
+++ b/test/cctest/compiler/test-run-machops.cc
@@ -6359,7 +6359,7 @@ TEST(RunTryTruncateFloat64ToUint64WithCheck) {
   FOR_FLOAT64_INPUTS(i) {
     if (*i < 18446744073709551616.0 && *i > -1) {
       // Conversions within this range should succeed.
-      CHECK_EQ(static_cast<uint64_t>(*i), m.Call(*i));
+      CHECK_EQ(static_cast<uint64_t>(*i), static_cast<uint64_t>(m.Call(*i)));
       CHECK_NE(0, success);
     } else {
       m.Call(*i);