[MC] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).

llvm-svn: 294813

llvm/lib/MC/MCLinkerOptimizationHint.cpp

@@ -1,4 +1,4 @@
-//===-- llvm/MC/MCLinkerOptimizationHint.cpp ----- LOH handling -*- C++ -*-===//
+//===- llvm/MC/MCLinkerOptimizationHint.cpp ----- LOH handling ------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -9,9 +9,11 @@
 
 #include "llvm/MC/MCLinkerOptimizationHint.h"
 #include "llvm/MC/MCAsmLayout.h"
-#include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCMachObjectWriter.h"
 #include "llvm/Support/LEB128.h"
+#include "llvm/Support/raw_ostream.h"
+#include <cstddef>
+#include <cstdint>
 
 using namespace llvm;
 
@@ -41,14 +43,14 @@ void MCLOHDirective::emit(MachObjectWriter &ObjWriter,
 uint64_t MCLOHDirective::getEmitSize(const MachObjectWriter &ObjWriter,
                                      const MCAsmLayout &Layout) const {
   class raw_counting_ostream : public raw_ostream {
-    uint64_t Count;
+    uint64_t Count = 0;
 
     void write_impl(const char *, size_t size) override { Count += size; }
 
     uint64_t current_pos() const override { return Count; }
 
   public:
-    raw_counting_ostream() : Count(0) {}
+    raw_counting_ostream() = default;
     ~raw_counting_ostream() override { flush(); }
   };