$.Analysis.Text: reimplement to rely on the internal implementation

TN: S521-032

langkit/compile_context.py

@@ -871,7 +871,7 @@ class CompileCtx(object):
         # Avoid a warning about unused documentation when there are no
         # synthetic nodes.
         if not self.synthetic_nodes:
-            _ = self.documentations['langkit.synthetic_nodes']
+            self.documentations['langkit.synthetic_nodes']
 
         # Check that the environment hook is bound if the language spec uses
         # it.

langkit/templates/pkg_analysis_body_ada.mako

@@ -882,7 +882,7 @@ package body ${ada_lib_name}.Analysis is
    function Text (Node : ${root_entity.api_name}'Class) return Text_Type is
    begin
       Check_Safety_Net (Node.Safety_Net);
-      return Text (Node.Token_Start, Node.Token_End);
+      return Text (Node.Internal.Node);
    end Text;
 
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