Promote STRINGIFY to macros.h

Marlin/language.h

@@ -3,8 +3,7 @@
 
 #include "Configuration.h"
 
-#define LANGUAGE_CONCAT(M)       #M
+#define GENERATE_LANGUAGE_INCLUDE(M)  STRINGIFY_(language_##M.h)
-#define GENERATE_LANGUAGE_INCLUDE(M)  LANGUAGE_CONCAT(language_##M.h)
 
 
 // NOTE: IF YOU CHANGE LANGUAGE FILES OR MERGE A FILE WITH CHANGES
@@ -88,10 +87,6 @@
 #endif
 
 
-#define STRINGIFY_(n) #n
-#define STRINGIFY(n) STRINGIFY_(n)
-
-
 // Common LCD messages
 
   /* nothing here yet */

Marlin/macros.h

@@ -1,6 +1,10 @@
 #ifndef MACROS_H
 #define MACROS_H
 
+// Macros to make a string from a macro
+#define STRINGIFY_(n) #n
+#define STRINGIFY(n) STRINGIFY_(n)
+
 // Macros for bit masks
 #define TEST(n,b) (((n)&_BV(b))!=0)
 #define SBI(n,b) (n |= _BV(b))