[turbofan] Build s/NULL/nullptr/g and CHECK(x != nullptr) to CHECK_NOT_NULL(x).

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

Index: src/compiler/mips/code-generator-mips.cc
diff --git a/src/compiler/mips/code-generator-mips.cc b/src/compiler/mips/code-generator-mips.cc
index c1f722d30e2674a68753fea16b16c706e7300aa9..aac516f92bf9c81293a4e3914be5549fd2160a58 100644
--- a/src/compiler/mips/code-generator-mips.cc
+++ b/src/compiler/mips/code-generator-mips.cc
@@ -118,7 +118,7 @@ class MipsOperandConverter final : public InstructionOperandConverter {
   MemOperand MemoryOperand(size_t index = 0) { return MemoryOperand(&index); }
 
   MemOperand ToMemOperand(InstructionOperand* op) const {
-    DCHECK(op != NULL);
+    DCHECK_NOT_NULL(op);
     DCHECK(op->IsStackSlot() || op->IsDoubleStackSlot());
     FrameOffset offset = frame_access_state()->GetFrameOffset(
         AllocatedOperand::cast(op)->index());
@@ -1221,7 +1221,7 @@ void CodeGenerator::AssembleArchBranch(Instruction* instr, BranchInfo* branch) {
         !__ IsDoubleZeroRegSet()) {
       __ Move(kDoubleRegZero, 0.0);
     }
-    __ BranchF32(tlabel, NULL, cc, left, right);
+    __ BranchF32(tlabel, nullptr, cc, left, right);
   } else if (instr->arch_opcode() == kMipsCmpD) {
     if (!convertCondition(branch->condition, cc)) {
       UNSUPPORTED_COND(kMips64CmpD, branch->condition);
@@ -1232,7 +1232,7 @@ void CodeGenerator::AssembleArchBranch(Instruction* instr, BranchInfo* branch) {
         !__ IsDoubleZeroRegSet()) {
       __ Move(kDoubleRegZero, 0.0);
     }
-    __ BranchF64(tlabel, NULL, cc, left, right);
+    __ BranchF64(tlabel, nullptr, cc, left, right);
   } else {
     PrintF("AssembleArchBranch Unimplemented arch_opcode: %d\n",
            instr->arch_opcode());
@@ -1541,7 +1541,7 @@ void CodeGenerator::AssembleReturn() {
 
 void CodeGenerator::AssembleMove(InstructionOperand* source,
                                  InstructionOperand* destination) {
-  MipsOperandConverter g(this, NULL);
+  MipsOperandConverter g(this, nullptr);
   // Dispatch on the source and destination operand kinds.  Not all
   // combinations are possible.
   if (source->IsRegister()) {
@@ -1647,7 +1647,7 @@ void CodeGenerator::AssembleMove(InstructionOperand* source,
 
 void CodeGenerator::AssembleSwap(InstructionOperand* source,
                                  InstructionOperand* destination) {
-  MipsOperandConverter g(this, NULL);
+  MipsOperandConverter g(this, nullptr);
   // Dispatch on the source and destination operand kinds.  Not all
   // combinations are possible.
   if (source->IsRegister()) {