win: static_cast to uint64_t rather than implicit_cast, to avoid warnings

util/misc/clock_test.cc

Index: util/misc/clock_test.cc
diff --git a/util/misc/clock_test.cc b/util/misc/clock_test.cc
index d06afd6728aa196ca1e3de1ab9e2996aa6e1b6a3..ffc5e4943a260c1f374c615ef2713275d5ea64f7 100644
--- a/util/misc/clock_test.cc
+++ b/util/misc/clock_test.cc
@@ -69,13 +69,13 @@ TEST(Clock, SleepNanoseconds) {
   const uint64_t kTestData[] = {
       0,
       1,
-      implicit_cast<uint64_t>(1E3),  // 1 microsecond
-      implicit_cast<uint64_t>(1E4),  // 10 microseconds
-      implicit_cast<uint64_t>(1E5),  // 100 microseconds
-      implicit_cast<uint64_t>(1E6),  // 1 millisecond
-      implicit_cast<uint64_t>(1E7),  // 10 milliseconds
-      implicit_cast<uint64_t>(2E7),  // 20 milliseconds
-      implicit_cast<uint64_t>(5E7),  // 50 milliseconds
+      static_cast<uint64_t>(1E3),  // 1 microsecond
+      static_cast<uint64_t>(1E4),  // 10 microseconds
+      static_cast<uint64_t>(1E5),  // 100 microseconds
+      static_cast<uint64_t>(1E6),  // 1 millisecond
+      static_cast<uint64_t>(1E7),  // 10 milliseconds
+      static_cast<uint64_t>(2E7),  // 20 milliseconds
+      static_cast<uint64_t>(5E7),  // 50 milliseconds
   };
 
   for (size_t index = 0; index < arraysize(kTestData); ++index) {