Handle IO::ArgFiles.lines(Inf)

Base everything off the common case (much more similar to IO::Handle.lines now).

src/core/IO/ArgFiles.pm

@@ -115,48 +115,10 @@ my class IO::ArgFiles is IO::Handle {
             }
         }.new(self, $!ins, -> { self!next-io }));
     }
-    multi method lines($limit = *) {
-        self.lines
-    }
-    multi method lines(Int() $limit) {
-        Seq.new(class :: does Iterator {
-            has $!args;
-            has $!iter;
-            has $!next-io;
-            has Int $!ins;
-
-            method new(\args, \ins, \next-io) {
-                my \iter = nqp::create(self);
-                nqp::bindattr(iter, self, '$!args', args);
-                nqp::bindattr(iter, self, '$!ins', ins);
-                nqp::bindattr(iter, self, '$!next-io', next-io);
-                my $io = next-io.();
-                if $io.defined {
-                    nqp::bindattr(iter, self, '$!iter', $io.lines(:close).iterator);
-                }
-                else {
-                    return $io if nqp::istype($io, Failure);
-                }
-                iter
-            }
-
-            method pull-one() {
-                nqp::if(nqp::iseq_I(nqp::decont($limit), nqp::decont($!ins)),
-                  IterationEnd,
-                  nqp::stmts(
-                    (my \value = $!iter.pull-one),
-                    nqp::if(nqp::eqaddr(value, IterationEnd),
-                      nqp::stmts(
-                        (my $io = $!next-io.()),
-                        nqp::if(nqp::istype($io, Failure), return $io),
-                        nqp::unless(nqp::defined($io), return IterationEnd),
-                        ($!iter := $io.lines(:close).iterator),
-                        self.pull-one),
-                      nqp::stmts(
-                        ($!ins = nqp::add_I(nqp::decont($!ins), 1, Int)),
-                        value))))
-            }
-        }.new(self, $!ins, -> { self!next-io }));
+    multi method lines($limit) {
+        nqp::istype($limit,Whatever) || $limit == Inf
+          ?? self.lines
+          !! self.lines[ 0 .. $limit.Int - 1 ]
     }
 
     method slurp(IO::ArgFiles:D: |c) {