use stringized macros

* version.h (RUBY_COPYRIGHT): use stringized macros,
  RUBY_BIRTH_YEAR_STR and RUBY_RELEASE_YEAR_STR.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53478 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

version.h

@@ -13,6 +13,7 @@
 #endif
 #define ONLY_ONE_DIGIT(x) TOKEN_PASTE(10,x) < 1000
 #define WITH_ZERO_PADDING(x) TOKEN_PASTE(0,x)
+#define RUBY_BIRTH_YEAR_STR STRINGIZE(RUBY_BIRTH_YEAR)
 #define RUBY_RELEASE_YEAR_STR STRINGIZE(RUBY_RELEASE_YEAR)
 #if ONLY_ONE_DIGIT(RUBY_RELEASE_MONTH)
 #define RUBY_RELEASE_MONTH_STR STRINGIZE(WITH_ZERO_PADDING(RUBY_RELEASE_MONTH))
@@ -67,6 +68,6 @@
     "["RUBY_PLATFORM"]"
 # define RUBY_COPYRIGHT		    \
     "ruby - Copyright (C) "	    \
-    STRINGIZE(RUBY_BIRTH_YEAR)"-"   \
-    STRINGIZE(RUBY_RELEASE_YEAR)" " \
+    RUBY_BIRTH_YEAR_STR"-"   \
+    RUBY_RELEASE_YEAR_STR" " \
     RUBY_AUTHOR