Add a few missing headers for modularization/IWYU/etc

Several cases where class definitions are required for DenseMap pointer
traits handling.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@316803 91177308-0d34-0410-b5e6-96231b3b80d8

Author: dwblaikie

include/llvm/MC/MCWasmStreamer.h

@@ -10,16 +10,16 @@
 #ifndef LLVM_MC_MCWASMSTREAMER_H
 #define LLVM_MC_MCWASMSTREAMER_H
 
+#include "MCAsmBackend.h"
+#include "MCCodeEmitter.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/MC/MCDirectives.h"
 #include "llvm/MC/MCObjectStreamer.h"
 #include "llvm/MC/SectionKind.h"
 #include "llvm/Support/DataTypes.h"
 
 namespace llvm {
-class MCAsmBackend;
 class MCAssembler;
-class MCCodeEmitter;
 class MCExpr;
 class MCInst;
 class raw_ostream;

include/llvm/PassAnalysisSupport.h

@@ -19,6 +19,7 @@
 #ifndef LLVM_PASSANALYSISSUPPORT_H
 #define LLVM_PASSANALYSISSUPPORT_H
 
+#include "Pass.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include <cassert>

lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h

@@ -12,12 +12,12 @@
 
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/IR/DebugInfoMetadata.h"
 #include <utility>
 
 namespace llvm {
 
 class DILocalVariable;
-class DILocation;
 class MachineFunction;
 class MachineInstr;
 class TargetRegisterInfo;

lib/Target/ARM/MCTargetDesc/ARMAsmBackendDarwin.h

@@ -12,6 +12,7 @@
 
 #include "ARMAsmBackend.h"
 #include "llvm/BinaryFormat/MachO.h"
+#include "llvm/MC/MCObjectWriter.h"
 
 namespace llvm {
 class ARMAsmBackendDarwin : public ARMAsmBackend {

lib/Target/ARM/MCTargetDesc/ARMAsmBackendELF.h

@@ -12,6 +12,8 @@
 
 #include "ARMAsmBackend.h"
 #include "MCTargetDesc/ARMMCTargetDesc.h"
+#include "llvm/MC/MCObjectWriter.h"
+
 using namespace llvm;
 
 namespace {

lib/Target/ARM/MCTargetDesc/ARMAsmBackendWinCOFF.h

@@ -11,6 +11,7 @@
 #define LLVM_LIB_TARGET_ARM_ARMASMBACKENDWINCOFF_H
 
 #include "ARMAsmBackend.h"
+#include "llvm/MC/MCObjectWriter.h"
 using namespace llvm;
 
 namespace {