Wrap shared windows-nat code in windows_nat namespace

This wraps the shared windows-nat code in a windows_nat namespace.
This helps avoid name clashes.

gdb/ChangeLog
2020-04-08  Tom Tromey  <tromey@adacore.com>

	* windows-nat.c: Add "using namespace".
	* nat/windows-nat.h: Wrap contents in windows_nat namespace.
	* nat/windows-nat.c: Wrap contents in windows_nat namespace.

gdbserver/ChangeLog
2020-04-08  Tom Tromey  <tromey@adacore.com>

	* win32-low.h (struct win32_target_ops): Use qualified names where
	needed.
	* win32-i386-low.c: Add "using namespace".
	* win32-low.c: Add "using namespace".
	* win32-arm-low.c: Add "using namespace".

gdb/ChangeLog

@@ -1,3 +1,9 @@
+2020-04-08  Tom Tromey  <tromey@adacore.com>
+
+	* windows-nat.c: Add "using namespace".
+	* nat/windows-nat.h: Wrap contents in windows_nat namespace.
+	* nat/windows-nat.c: Wrap contents in windows_nat namespace.
+
 2020-04-08  Tom Tromey  <tromey@adacore.com>
 
 	* nat/windows-nat.h (struct windows_thread_info): Declare

gdb/nat/windows-nat.c

@@ -19,6 +19,9 @@
 #include "gdbsupport/common-defs.h"
 #include "nat/windows-nat.h"
 
+namespace windows_nat
+{
+
 windows_thread_info::~windows_thread_info ()
 {
   CloseHandle (h);
@@ -65,3 +68,5 @@ windows_thread_info::resume ()
     }
   suspended = 0;
 }
+
+}

gdb/nat/windows-nat.h

@@ -21,6 +21,9 @@
 
 #include <windows.h>
 
+namespace windows_nat
+{
+
 /* Thread information structure used to track extra information about
    each thread.  */
 struct windows_thread_info
@@ -87,4 +90,6 @@ struct windows_thread_info
   gdb::unique_xmalloc_ptr<char> name;
 };
 
+}
+
 #endif

gdb/windows-nat.c

@@ -75,6 +75,8 @@
 #define STATUS_WX86_BREAKPOINT 0x4000001F
 #define STATUS_WX86_SINGLE_STEP 0x4000001E
 
+using namespace windows_nat;
+
 #define AdjustTokenPrivileges		dyn_AdjustTokenPrivileges
 #define DebugActiveProcessStop		dyn_DebugActiveProcessStop
 #define DebugBreakProcess		dyn_DebugBreakProcess

gdbserver/ChangeLog

@@ -1,3 +1,11 @@
+2020-04-08  Tom Tromey  <tromey@adacore.com>
+
+	* win32-low.h (struct win32_target_ops): Use qualified names where
+	needed.
+	* win32-i386-low.c: Add "using namespace".
+	* win32-low.c: Add "using namespace".
+	* win32-arm-low.c: Add "using namespace".
+
 2020-04-08  Tom Tromey  <tromey@adacore.com>
 
 	* win32-low.c (delete_thread_info): Don't call CloseHandle.

gdbserver/win32-arm-low.cc

@@ -18,6 +18,8 @@
 #include "server.h"
 #include "win32-low.h"
 
+using namespace windows_nat;
+
 #ifndef CONTEXT_FLOATING_POINT
 #define CONTEXT_FLOATING_POINT 0
 #endif

gdbserver/win32-i386-low.cc

@@ -26,6 +26,8 @@
 #include "tdesc.h"
 #include "x86-tdesc.h"
 
+using namespace windows_nat;
+
 #ifndef CONTEXT_EXTENDED_REGISTERS
 #define CONTEXT_EXTENDED_REGISTERS 0
 #endif

gdbserver/win32-low.cc

@@ -36,6 +36,8 @@
 #include "gdbsupport/common-inferior.h"
 #include "gdbsupport/gdb_wait.h"
 
+using namespace windows_nat;
+
 #ifndef USE_WIN32API
 #include <sys/cygwin.h>
 #endif

gdbserver/win32-low.h

@@ -40,23 +40,25 @@ struct win32_target_ops
   void (*initial_stuff) (void);
 
   /* Fetch the context from the inferior.  */
-  void (*get_thread_context) (windows_thread_info *th);
+  void (*get_thread_context) (windows_nat::windows_thread_info *th);
 
   /* Called just before resuming the thread.  */
-  void (*prepare_to_resume) (windows_thread_info *th);
+  void (*prepare_to_resume) (windows_nat::windows_thread_info *th);
 
   /* Called when a thread was added.  */
-  void (*thread_added) (windows_thread_info *th);
+  void (*thread_added) (windows_nat::windows_thread_info *th);
 
   /* Fetch register from gdbserver regcache data.  */
   void (*fetch_inferior_register) (struct regcache *regcache,
-				   windows_thread_info *th, int r);
+				   windows_nat::windows_thread_info *th,
+				   int r);
 
   /* Store a new register value into the thread context of TH.  */
   void (*store_inferior_register) (struct regcache *regcache,
-				   windows_thread_info *th, int r);
+				   windows_nat::windows_thread_info *th,
+				   int r);
 
-  void (*single_step) (windows_thread_info *th);
+  void (*single_step) (windows_nat::windows_thread_info *th);
 
   const unsigned char *breakpoint;
   int breakpoint_len;
@@ -143,7 +145,7 @@ public:
 };
 
 /* Retrieve the context for this thread, if not already retrieved.  */
-extern void win32_require_context (windows_thread_info *th);
+extern void win32_require_context (windows_nat::windows_thread_info *th);
 
 /* Map the Windows error number in ERROR to a locale-dependent error
    message string and return a pointer to it.  Typically, the values