move GCC version check from marshal.c to configure.ac

I think it should be done in configure


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64862 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

configure.ac

@@ -238,6 +238,10 @@ AS_IF([test "$GCC" = yes], [
     linker_flag=
 ])
 
+AS_IF([test "$GCC" = yes -a "$gcc_major" -lt 3 ], [
+    AC_MSG_ERROR([too old GCC])
+])
+
 RUBY_PROG_GNU_LD
 RUBY_CPPOUTFILE
 

marshal.c

@@ -9,10 +9,6 @@
 
 **********************************************************************/
 
-#if defined __GNUC__ && __GNUC__ < 3
-# error too old GCC
-#endif
-
 #include "ruby/ruby.h"
 #include "ruby/io.h"
 #include "internal.h"