main.c: RUBY_DEBUG_ENV in devel

* main.c (RUBY_DEBUG_ENV): default to enabled in the development
  version.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59213 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

main.c

@@ -15,6 +15,9 @@
 #ifdef HAVE_LOCALE_H
 #include <locale.h>
 #endif
+#if RUBY_DEVEL && !defined RUBY_DEBUG_ENV
+# define RUBY_DEBUG_ENV 1
+#endif
 #if defined RUBY_DEBUG_ENV && !RUBY_DEBUG_ENV
 # undef RUBY_DEBUG_ENV
 #endif