[PRISM] Fix `PM_PARENTHESES_NODE`

In #9101 I only accounted for an empty paren. This change implements the
`PM_PARENTHESES_NODE` for when it's `nil` and when it's an expression.

Code:

```ruby
defined?(("a"))
```

```
"********* Ruby *************"
== disasm: #<ISeq:<compiled>@<compiled>:0 (0,0)-(0,15)>
0000 putobject                              "expression"
0002 leave

"********* PRISM *************"
== disasm: #<ISeq:<compiled>@<compiled>:0 (0,0)-(0,15)>
0000 putobject                              "expression"
0002 leave
```

prism_compile.c

@@ -1443,9 +1443,18 @@ pm_compile_defined_expr0(rb_iseq_t *iseq, const pm_node_t *node, LINK_ANCHOR *co
     enum defined_type dtype = DEFINED_NOT_DEFINED;
     switch (PM_NODE_TYPE(node)) {
       case PM_NIL_NODE:
-      case PM_PARENTHESES_NODE:
         dtype = DEFINED_NIL;
         break;
+      case PM_PARENTHESES_NODE: {
+          pm_parentheses_node_t *parentheses_node = (pm_parentheses_node_t *) node;
+
+          if (parentheses_node->body == NULL) {
+              dtype = DEFINED_NIL;
+          } else {
+              dtype = DEFINED_EXPR;
+          }
+          break;
+      }
       case PM_SELF_NODE:
         dtype = DEFINED_SELF;
         break;

test/ruby/test_compile_prism.rb

@@ -158,6 +158,7 @@ module Prism
       assert_prism_eval("if defined? A; end")
 
       assert_prism_eval("defined?(())")
+      assert_prism_eval("defined?(('1'))")
     end
 
     def test_GlobalVariableReadNode