readnum.c: provide obsolete functions.

- mrb_int_read()
- mrb_float_read()

Both functions should not be use and this file should not be linked.
This is just for compatibility.

src/readnum.c

@@ -0,0 +1,43 @@
+/* this file defines obsolete functions: mrb_int_read() and mrb_float_read() */
+/* use mrb_read_int() and mrb_read_float() instead */
+
+#include <mruby.h>
+#include <mruby/numeric.h>
+#include <errno.h>
+
+/* mrb_int_read(): read mrb_int from a string (base 10 only) */
+/* const char *p - string to read                            */
+/* const char *e - end of string                             */
+/* char **endp   - end of parsed integer                     */
+
+/* if integer overflows, errno will be set to ERANGE         */
+/* also endp will be set to NULL on overflow                 */
+MRB_API mrb_int
+mrb_int_read(const char *p, const char *e, char **endp)
+{
+  mrb_int n;
+
+  if (!mrb_read_int(p, e, endp, &n)) {
+    if (endp) *endp = NULL;
+    errno = ERANGE;
+    return MRB_INT_MAX;
+  }
+  if (endp) *endp = (char*)p;
+  return n;
+}
+
+#ifndef MRB_NO_FLOAT
+//#include <string.h>
+//#include <math.h>
+
+MRB_API double
+mrb_float_read(const char *str, char **endp)
+{
+  double d;
+
+  if (!mrb_read_float(str, endp, &d)) {
+    errno = ERANGE;
+  }
+  return d;
+}
+#endif