Sink COFF.h MC include into .cpp files

This prevents MC clients from getting COFF.h, which conflicts with
winnt.h macros. Also a minor IWYU cleanup. Now the only public headers
including COFF.h are in Object, and they actually need it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246784 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCSectionCOFF.h

@@ -16,7 +16,6 @@
 
 #include "llvm/ADT/StringRef.h"
 #include "llvm/MC/MCSection.h"
-#include "llvm/Support/COFF.h"
 
 namespace llvm {
 class MCSymbol;

lib/CodeGen/TargetLoweringObjectFileImpl.cpp

@@ -32,6 +32,7 @@
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSymbolELF.h"
 #include "llvm/MC/MCValue.h"
+#include "llvm/Support/COFF.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Support/ELF.h"
 #include "llvm/Support/ErrorHandling.h"

lib/MC/MCContext.cpp

@@ -23,6 +23,7 @@
 #include "llvm/MC/MCSymbolCOFF.h"
 #include "llvm/MC/MCSymbolELF.h"
 #include "llvm/MC/MCSymbolMachO.h"
+#include "llvm/Support/COFF.h"
 #include "llvm/Support/ELF.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FileSystem.h"

lib/MC/MCObjectFileInfo.cpp

@@ -16,6 +16,7 @@
 #include "llvm/MC/MCSectionCOFF.h"
 #include "llvm/MC/MCSectionELF.h"
 #include "llvm/MC/MCSectionMachO.h"
+#include "llvm/Support/COFF.h"
 using namespace llvm;
 
 static bool useCompactUnwind(const Triple &T) {

lib/MC/MCSectionCOFF.cpp

@@ -11,6 +11,7 @@
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCSymbol.h"
+#include "llvm/Support/COFF.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 

lib/Target/X86/X86TargetObjectFile.cpp

@@ -16,6 +16,7 @@
 #include "llvm/MC/MCSectionCOFF.h"
 #include "llvm/MC/MCSectionELF.h"
 #include "llvm/MC/MCValue.h"
+#include "llvm/Support/COFF.h"
 #include "llvm/Support/Dwarf.h"
 #include "llvm/Target/TargetLowering.h"