Include I/O subs in the setting.

nqp-src/NQPCORE.setting

@@ -601,6 +601,54 @@ my class NQPCapture {
 }
 
 # From src\core\IO.pm
+
+=begin
+
+IO Methods and Functions
+
+=end
+
+=begin item open
+Open file.
+=end item
+
+sub open($filename, :$r, :$w, :$a, :$bin) {
+    my $mode := $w ?? 'w' !! ($a ?? 'wa' !! 'r');
+    my $handle := nqp::open($filename, $mode);
+    nqp::setencoding($handle, $bin ?? 'binary' !! 'utf8');
+    $handle;
+}
+
+=begin item close
+Close handle
+=end item
+
+sub close($handle) {
+    nqp::closefh($handle);
+}
+
+=begin item slurp
+Returns the contents of C<$filename> as a single string.
+=end item
+
+sub slurp ($filename) {
+    my $handle := open($filename, :r);
+    my $contents := nqp::readallfh($handle);
+    nqp::closefh($handle);
+    $contents;
+}
+
+
+=begin item spew
+Write the string value of C<$contents> to C<$filename>.
+=end item
+
+sub spew($filename, $contents) {
+    my $handle := open($filename, :w);
+    nqp::printfh($handle, $contents);
+    nqp::closefh($handle);
+}
+
 sub print(*@args) {
     for @args {
         nqp::print($_);