Wantify arglist in postcircumfix:sym<( )>

Fixes 131502: https://rt.perl.org/Public/Bug/Display.html?id=131502

Not 100% sure this is the right place for the want, since ticket
affects only WhateverCode's code in the args and, say,
`-> $ {  }(* == 42, -> $a { $a == 70 })` will warn only about
the `==` in WhateverCode, not the one in the block.

src/Perl6/Actions.nqp

@@ -7617,7 +7617,7 @@ class Perl6::Actions is HLL::Actions does STDActions {
     }
 
     method postcircumfix:sym<( )>($/) {
-        make $<arglist>.ast;
+        make wanted($<arglist>.ast, 'postcircumfix()/args');
     }
 
     method value:sym<quote>($/) {