$ perlbrew exec --with 5.24.4,5.26.2 perl -MO=Concise -wMstrict -e 'my %hash; print $hash{-foo}'

perl-5.24.4
==========
b  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 2 -e:1) v:*,&,{,x*,x&,x$,$ ->3
3     <0> padhv[%hash:2,3] vM/LVINTRO ->4
4     <;> nextstate(main 3 -e:1) v:*,&,{,x*,x&,x$,$ ->5
a     <@> print vK ->b
5        <0> pushmark s ->6
9        <2> helem sK/2 ->a
6           <0> padhv[%hash:2,3] sR ->7
8           <1> negate[t2] sK/1 ->9
7              <$> const(PV "foo") s/BARE ->8
-e syntax OK


perl-5.26.2
==========
8  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 2 -e:1) v:*,&,{,x*,x&,x$,$ ->3
3     <0> padhv[%hash:2,3] vM/LVINTRO ->4
4     <;> nextstate(main 3 -e:1) v:*,&,{,x*,x&,x$,$ ->5
7     <@> print vK ->8
5        <0> pushmark s ->6
-        <1> ex-helem sK/2 ->7
6           <+> multideref($hash{"-foo"}) sK ->7
-              <0> ex-padhv sR ->6
-e syntax OK