[lldb] Remove bogus ProcessMonitor forward-decls

This class is not used in those files.

Author: labath

lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_arm.h

@@ -14,8 +14,6 @@
 #include "lldb/Target/RegisterContext.h"
 #include "lldb/Utility/Log.h"
 
-class ProcessMonitor;
-
 class RegisterContextPOSIX_arm : public lldb_private::RegisterContext {
 public:
   RegisterContextPOSIX_arm(

lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_arm64.h

@@ -14,8 +14,6 @@
 #include "lldb/Target/RegisterContext.h"
 #include "lldb/Utility/Log.h"
 
-class ProcessMonitor;
-
 class RegisterContextPOSIX_arm64 : public lldb_private::RegisterContext {
 public:
   RegisterContextPOSIX_arm64(

lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_mips64.h

@@ -14,10 +14,6 @@
 #include "lldb/Target/RegisterContext.h"
 #include "lldb/Utility/Log.h"
 
-using namespace lldb_private;
-
-class ProcessMonitor;
-
 class RegisterContextPOSIX_mips64 : public lldb_private::RegisterContext {
 public:
 

lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_powerpc.h

@@ -14,8 +14,6 @@
 #include "lldb/Target/RegisterContext.h"
 #include "lldb/Utility/Log.h"
 
-class ProcessMonitor;
-
 // Internal codes for all powerpc registers.
 enum {
   k_first_gpr_powerpc,

lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_s390x.h

@@ -15,8 +15,6 @@
 #include "lldb/Target/RegisterContext.h"
 #include "lldb/Utility/Log.h"
 
-class ProcessMonitor;
-
 class RegisterContextPOSIX_s390x : public lldb_private::RegisterContext {
 public:
   RegisterContextPOSIX_s390x(

lldb/source/Plugins/Process/Utility/RegisterContextPOSIX_x86.h

@@ -15,8 +15,6 @@
 #include "lldb/Target/RegisterContext.h"
 #include "lldb/Utility/Log.h"
 
-class ProcessMonitor;
-
 class RegisterContextPOSIX_x86 : public lldb_private::RegisterContext {
 public:
   RegisterContextPOSIX_x86(lldb_private::Thread &thread,