[turbofan] Fix more -Wsign-compare warnings.

src/compiler/x64/code-generator-x64.cc

Index: src/compiler/x64/code-generator-x64.cc
diff --git a/src/compiler/x64/code-generator-x64.cc b/src/compiler/x64/code-generator-x64.cc
index 841606a4a463bfb1b08f1c749fe01cf10900eb74..7c090aa2b062aa5b60a80314d813db310833a8a1 100644
--- a/src/compiler/x64/code-generator-x64.cc
+++ b/src/compiler/x64/code-generator-x64.cc
@@ -447,7 +447,7 @@ class WasmOutOfLineTrap final : public OutOfLineCode {
     OutOfLineCode* ool;                                                      \
     if (instr->InputAt(3)->IsRegister()) {                                   \
       auto length = i.InputRegister(3);                                      \
-      DCHECK_EQ(0, index2);                                                  \
+      DCHECK_EQ(0u, index2);                                                 \
       __ cmpl(index1, length);                                               \
       ool = new (zone()) OutOfLineLoadNaN(this, result);                     \
     } else {                                                                 \
@@ -502,7 +502,7 @@ class WasmOutOfLineTrap final : public OutOfLineCode {
     OutOfLineCode* ool;                                                        \
     if (instr->InputAt(3)->IsRegister()) {                                     \
       auto length = i.InputRegister(3);                                        \
-      DCHECK_EQ(0, index2);                                                    \
+      DCHECK_EQ(0u, index2);                                                   \
       __ cmpl(index1, length);                                                 \
       ool = new (zone()) OutOfLineLoadZero(this, result);                      \
     } else {                                                                   \
@@ -559,7 +559,7 @@ class WasmOutOfLineTrap final : public OutOfLineCode {
     auto value = i.InputDoubleRegister(4);                                   \
     if (instr->InputAt(3)->IsRegister()) {                                   \
       auto length = i.InputRegister(3);                                      \
-      DCHECK_EQ(0, index2);                                                  \
+      DCHECK_EQ(0u, index2);                                                 \
       Label done;                                                            \
       __ cmpl(index1, length);                                               \
       __ j(above_equal, &done, Label::kNear);                                \
@@ -614,7 +614,7 @@ class WasmOutOfLineTrap final : public OutOfLineCode {
     auto index2 = i.InputUint32(2);                                            \
     if (instr->InputAt(3)->IsRegister()) {                                     \
       auto length = i.InputRegister(3);                                        \
-      DCHECK_EQ(0, index2);                                                    \
+      DCHECK_EQ(0u, index2);                                                   \
       Label done;                                                              \
       __ cmpl(index1, length);                                                 \
       __ j(above_equal, &done, Label::kNear);                                  \
@@ -2508,7 +2508,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* pop) {
   if (pop->IsImmediate()) {
     DCHECK_EQ(Constant::kInt32, g.ToConstant(pop).type());
     pop_size += g.ToConstant(pop).ToInt32() * kPointerSize;
-    CHECK_LT(pop_size, std::numeric_limits<int>::max());
+    CHECK_LT(pop_size, static_cast<size_t>(std::numeric_limits<int>::max()));
     __ Ret(static_cast<int>(pop_size), rcx);
   } else {
     Register pop_reg = g.ToRegister(pop);