Add new ++ macro to core-macros.lfe.
Add new ++ macro to core-macros.lfe.

lfe/lfe,rvirding/lfe,yurrriq/lfe,arpunk/lfe,jjl/lfe,yurrriq/lfe,jjhoo/lfe,bsmr-erlang/lfe,lfe/lfe,oubiwann/lfe,rvirding/lfe,bsmr-erlang/lfe,jjhoo/lfe,jjl/lfe,arpunk/lfe,oubiwann/lfe