sbcsgen.pl uses 'select' to point Perl at a different default output

handle. Revert that when we hackily call it from mkfiles.pl, so that
if I have a need to insert diagnostics in the latter they won't go
into the end of sbcsdat.c.

[originally from svn r10013]

mkfiles.pl

@@ -46,7 +46,7 @@ open IN, "Recipe" or do {
 # HACK: One of the source files in `charset' is auto-generated by
 # sbcsgen.pl. We need to generate that _now_, before attempting
 # dependency analysis.
-eval 'chdir "charset"; require "sbcsgen.pl"; chdir ".."';
+eval 'chdir "charset"; require "sbcsgen.pl"; chdir ".."; select STDOUT;';
 
 @srcdirs = ("./");