core: Move M2_PTR_SIZE, M2_CELL_SIZE to include file.

* lib/posix/getenv.c (M2_PTR_SIZE),
lib/posix/setenv.c (M2_PTR_SIZE): Move definition...
* include/mes/lib-mini.h (M2_PTR_SIZE): ...here.
* src/gc.c (M2_CELL_SIZE),
src/symbol.c (M2_CELL_SIZE),
src/test/gc.c (M2_CELL_SIZE),
src/vector.c (M2_CELL_SIZE): Move definition...
* include/mes/mes.h (M2_CELL_SIZE): ...here.

include/mes/lib-mini.h

@@ -37,6 +37,15 @@
 #define STDERR 2
 #endif
 
+/* M2-Planet does not support pointer arithmetic.  Explicitly compensate
+   for that by multiplying with M2_PTR_SIZE when using (char)
+   pointers. */
+#if __M2__
+#define M2_PTR_SIZE 4
+#else
+#define M2_PTR_SIZE 1
+#endif
+
 extern char **environ;
 extern int __stdin;
 extern int __stdout;

include/mes/mes.h

@@ -53,6 +53,15 @@ struct scm
   };
 };
 
+/* M2-Planet does not support pointer arithmetic.  Explicitly compensate
+   for that by multiplying with M2_CELL_SIZE when using cell
+   pointers. */
+#if __M2__
+#define M2_CELL_SIZE 12
+#else
+#define M2_CELL_SIZE 1
+#endif
+
 /* mes */
 extern char *g_datadir;
 extern int g_debug;

lib/posix/getenv.c

@@ -22,12 +22,6 @@
 #include <string.h>
 #include <stdlib.h>
 
-#if __M2__
-#define M2_PTR_SIZE 4
-#else
-#define M2_PTR_SIZE 1
-#endif
-
 char *
 getenv (char const *s)
 {

lib/posix/setenv.c

@@ -22,12 +22,6 @@
 #include <string.h>
 #include <stdlib.h>
 
-#if __M2__
-#define M2_PTR_SIZE 4
-#else
-#define M2_PTR_SIZE 1
-#endif
-
 int
 setenv (char const *s, char const *v, int overwrite_p)
 {

src/gc.c

@@ -31,12 +31,6 @@
 
 int g_dump_filedes;
 
-#if __M2__
-#define M2_CELL_SIZE 12
-#else
-#define M2_CELL_SIZE 1U
-#endif
-
 char *
 cell_bytes (struct scm *x)
 {

src/symbol.c

@@ -23,12 +23,6 @@
 
 #include <string.h>
 
-#if __M2__
-#define M2_CELL_SIZE 12
-#else
-#define M2_CELL_SIZE 1
-#endif
-
 struct scm *
 init_symbol (struct scm *x, long type, char const *name)
 {

src/test/gc.c

@@ -24,12 +24,6 @@
 #include <stdlib.h>
 #include <string.h>
 
-#if __M2__
-#define M2_CELL_SIZE 12
-#else
-#define M2_CELL_SIZE 1
-#endif
-
 int g_debug;
 
 void

src/vector.c

@@ -21,12 +21,6 @@
 #include "mes/lib.h"
 #include "mes/mes.h"
 
-#if __M2__
-#define M2_CELL_SIZE 12
-#else
-#define M2_CELL_SIZE 1
-#endif
-
 struct scm *
 make_vector_ (long k, struct scm *e)
 {