[turbofan] Fix more -Wsign-compare warnings.

test/cctest/compiler/test-run-load-store.cc

Index: test/cctest/compiler/test-run-load-store.cc
diff --git a/test/cctest/compiler/test-run-load-store.cc b/test/cctest/compiler/test-run-load-store.cc
index b4970612a5f45dcd3a02e888d2c0d825f776d42d..559e6fd02ad2a3965a9a07166741c8cade6a5ac6 100644
--- a/test/cctest/compiler/test-run-load-store.cc
+++ b/test/cctest/compiler/test-run-load-store.cc
@@ -278,7 +278,7 @@ void RunUnalignedLoadStoreUnalignedAccess(MachineType rep) {
   CType out_buffer[2];
   byte* raw;
 
-  for (int x = 0; x < sizeof(CType); x++) {
+  for (int x = 0; x < static_cast<int>(sizeof(CType)); x++) {
     int y = sizeof(CType) - x;
 
     raw = reinterpret_cast<byte*>(&in);
@@ -523,7 +523,7 @@ void RunLoadStoreSignExtend64(TestAlignment t) {
 void RunLoadStoreZeroExtend64(TestAlignment t) {
   if (kPointerSize < 8) return;
   uint64_t buffer[5];
-  RawMachineAssemblerTester<int64_t> m;
+  RawMachineAssemblerTester<uint64_t> m;
   Node* load8 = m.LoadFromPointer(LSB(&buffer[0], 1), MachineType::Uint8());
   if (t == TestAlignment::kAligned) {
     Node* load16 = m.LoadFromPointer(LSB(&buffer[0], 2), MachineType::Uint16());
@@ -1090,7 +1090,7 @@ void TestRunOobCheckedLoadT_pseudo(uint64_t x, bool length_is_immediate) {
   }
 
   // slightly out-of-bounds accesses.
-  for (int32_t i = kNumElems; i < kNumElems + 30; i++) {
+  for (uint32_t i = kNumElems; i < kNumElems + 30; i++) {
     uint32_t offset = static_cast<uint32_t>(i * sizeof(MemType));
     CHECK_EQ(kReturn, m.Call(offset + pseudo_base, kLength));
     CheckOobValue(result);