Add var name to typecheck error for constants

The initial RakuAST implementation was added in e9f438f
and this just adds the name of the variable to the message in the same
manner as the legacy implementation.

src/Raku/ast/variable-declaration.rakumod

@@ -351,8 +351,9 @@ class RakuAST::VarDeclaration::Constant
               self.get-implicit-lookups.AT-POS(0).resolution.compile-time-value;
 
             unless nqp::istype(nqp::what($!value), $type) {
+                my $name := nqp::getattr_s(self, RakuAST::VarDeclaration::Constant, '$!name');
                 self.add-sorry($resolver.build-exception('X::Comp::TypeCheck',
-                  operation => 'constant declaration',
+                  operation => 'constant declaration of ' ~ ($name || '<anon>'),
                   expected  => $type,
                   got       => $!value
                 ));