Add --moar-option="--option=value" option to Configure.pl
Add --moar-option="--option=value" option to Configure.pl

Let people who build Rakudo Star specify MoarVM build options
when running Configure.pl.  This is useful, for example, to
enable libffi and build a version of Star that does not require
an excutable stack -- see
http://www.nntp.perl.org/group/perl.perl6.compiler/2017/07/msg16192.html

rakudo/star,stmuk/star