Fixed not to make non-literal expression shareable [Feature #17273]

Non-literal expression which is not a part of a literal expression
is not a subject of `shareable_literal_value: literal`.

test/ruby/test_parse.rb

@@ -1189,6 +1189,7 @@ x = __ENCODING__
       B = [[2]]
       # shareable_constant_value: literal
       C = [["shareable", "constant#{nil}"]]
+      D = A
 
       [A, B, C]
     end;