message: [Initialization] Remove extra SwiftASTContext initialize and terminate
  This is already being handled in SystemInitializerFull. It doesn't need to
  happen in common, because other tools (like lldb-server) don't actually use
  SwiftASTContext.
diff: #include "lldb/Host/Host.h"
  #include "lldb/Host/HostInfo.h"
  #include "lldb/Symbol/ClangASTContext.h"
  -#include "lldb/Symbol/SwiftASTContext.h"
  #include "lldb/Utility/Log.h"
  #include "lldb/Utility/Reproducer.h"
  #include "lldb/Utility/Timer.h"
  @@ -103,7 +102,6 @@ llvm::Error SystemInitializerCommon::Initialize() {
  // Initialize plug-ins
  ClangASTContext::Initialize();
  - SwiftASTContext::Initialize();
  SwiftREPL::Initialize();
  @@ -134,7 +132,6 @@ void SystemInitializerCommon::Terminate() {
  ObjectContainerBSDArchive::Terminate();
  ClangASTContext::Terminate();
  - SwiftASTContext::Terminate();
  SwiftREPL::Terminate();
  