bignum.c (DBL_BIGDIG): make enum

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57178 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

bignum.c

@@ -6090,10 +6090,11 @@ big_shift(VALUE x, long n)
     return x;
 }
 
+enum {DBL_BIGDIG = ((DBL_MANT_DIG + BITSPERDIG) / BITSPERDIG)};
+
 static double
 big_fdiv(VALUE x, VALUE y, long ey)
 {
-#define DBL_BIGDIG ((DBL_MANT_DIG + BITSPERDIG) / BITSPERDIG)
     VALUE z;
     long l, ex;