[NFC] Header cleanup

Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595

1 files changed, 1 insertions, 3 deletions

diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp
index e326738..48dd89f 100644
--- a/llvm/lib/MC/MCContext.cpp
+++ b/llvm/lib/MC/MCContext.cpp
@@ -10,8 +10,8 @@
 #include "llvm/MC/MCContext.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/Twine.h"
-#include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCCodeView.h"
 #include "llvm/MC/MCDwarf.h"
 #include "llvm/MC/MCLabel.h"
@@ -27,11 +27,9 @@
 #include "llvm/Support/COFF.h"
 #include "llvm/Support/ELF.h"
 #include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/SourceMgr.h"
-#include <map>
 
 using namespace llvm;