Move M118 to cpp

Marlin/src/Marlin.cpp

   return false;
 }
 
-#include "gcode/host/M118.h"
 #include "gcode/host/M119.h"
 
 #include "gcode/control/M120_M121.h"

Marlin/src/gcode/gcode.cpp

 //
 // Placeholders for non-migrated codes
 //
-extern void gcode_M118();
 extern void gcode_M119();
 extern void gcode_M120();
 extern void gcode_M121();
       case 115: M115(); break;    // M115: Report capabilities
 
       case 117: M117(); break;    // M117: Set LCD message text, if possible
-      case 118: // M118: Display a message in the host console
-        gcode_M118();
-        break;
+      case 118: M118(); break;    // M118: Display a message in the host console
+
       case 119: // M119: Report endstop states
         gcode_M119();
         break;

Marlin/src/gcode/host/M118.h → Marlin/src/gcode/host/M118.cpp

  *
  */
 
+#include "../gcode.h"
+
 /**
  * M118: Display a message in the host console.
  *
  *  A  Append '// ' for an action command, as in OctoPrint
  *  E  Have the host 'echo:' the text
  */
-void gcode_M118() {
+void GcodeSuite::M118() {
   if (parser.boolval('E')) SERIAL_ECHO_START();
   if (parser.boolval('A')) SERIAL_ECHOPGM("// ");
   SERIAL_ECHOLN(parser.string_arg);