Huge speed boost by reducing the number of method calls in GCode.pm

lib/Slic3r/ExtrusionPath.pm

@@ -65,6 +65,11 @@ sub points {
     return $self->polyline;
 }
 
+sub last_point {
+    my $self = shift;
+    return $self->polyline->[-1];
+}
+
 sub is_perimeter {
     my $self = shift;
     return $self->role == EXTR_ROLE_PERIMETER