[Ada] Use pygments for Ada code examples of elaboration control

Only enhancement of formatting.

gcc/ada/

	* doc/gnat_ugn/elaboration_order_handling_in_gnat.rst: Change
	blocks from plain code to Ada.

gcc/ada/doc/gnat_ugn/elaboration_order_handling_in_gnat.rst

@@ -93,7 +93,7 @@ Elaboration code may appear in two distinct contexts:
   [body] compilation unit, ignoring any other package [body] declarations in
   between.
 
-  ::
+  .. code-block:: ada
 
      with Server;
      package Client is
@@ -116,7 +116,7 @@ Elaboration code may appear in two distinct contexts:
   bounded by the region starting from the ``begin`` keyword of the package body
   and ending at the ``end`` keyword of the package body.
 
-  ::
+  .. code-block:: ada
 
      package body Client is
         procedure Proc is
@@ -142,7 +142,7 @@ executed is referred to as **elaboration order**.
 
 Within a single unit, elaboration code is executed in sequential order.
 
-  ::
+  .. code-block:: ada
 
      package body Client is
         Result : ... := Server.Func;
@@ -190,13 +190,13 @@ factors:
 
 A program may have several elaboration orders depending on its structure.
 
-  ::
+  .. code-block:: ada
 
      package Server is
         function Func (Index : Integer) return Integer;
      end Server;
 
-  ::
+  .. code-block:: ada
 
      package body Server is
         Results : array (1 .. 5) of Integer := (1, 2, 3, 4, 5);
@@ -207,14 +207,14 @@ A program may have several elaboration orders depending on its structure.
         end Func;
      end Server;
 
-  ::
+  .. code-block:: ada
 
      with Server;
      package Client is
         Val : constant Integer := Server.Func (3);
      end Client;
 
-  ::
+  .. code-block:: ada
 
      with Client;
      procedure Main is begin null; end Main;
@@ -320,7 +320,7 @@ the desired elaboration order and avoiding ABE problems altogether.
   A library package which does not require a completing body does not suffer
   from ABE problems.
 
-  ::
+  .. code-block:: ada
 
      package Pack is
         generic
@@ -358,7 +358,7 @@ the desired elaboration order and avoiding ABE problems altogether.
   scenario can invoke a server target before the target body has been
   elaborated because the spec and body are effectively "glued" together.
 
-  ::
+  .. code-block:: ada
 
      package Server is
         pragma Elaborate_Body;
@@ -366,7 +366,7 @@ the desired elaboration order and avoiding ABE problems altogether.
         function Func return Integer;
      end Server;
 
-  ::
+  .. code-block:: ada
 
      package body Server is
         function Func return Integer is
@@ -375,7 +375,7 @@ the desired elaboration order and avoiding ABE problems altogether.
         end Func;
      end Server;
 
-  ::
+  .. code-block:: ada
 
      with Server;
      package Client is
@@ -425,13 +425,13 @@ depend on.
   be elaborated prior to the unit with the pragma. Note that other unrelated
   units may be elaborated in between the spec and the body.
 
-  ::
+  .. code-block:: ada
 
      package Server is
         function Func return Integer;
      end Server;
 
-  ::
+  .. code-block:: ada
 
      package body Server is
         function Func return Integer is
@@ -440,7 +440,7 @@ depend on.
         end Func;
      end Server;
 
-  ::
+  .. code-block:: ada
 
      with Server;
      pragma Elaborate (Server);
@@ -479,13 +479,13 @@ depend on.
   |withed| by the spec and body of the argument, recursively. Note that other
   unrelated units may be elaborated in between the spec and the body.
 
-  ::
+  .. code-block:: ada
 
      package Math is
         function Factorial (Val : Natural) return Natural;
      end Math;
 
-  ::
+  .. code-block:: ada
 
      package body Math is
         function Factorial (Val : Natural) return Natural is
@@ -494,7 +494,7 @@ depend on.
         end Factorial;
      end Math;
 
-  ::
+  .. code-block:: ada
 
      package Computer is
         type Operation_Kind is (None, Op_Factorial);
@@ -504,7 +504,7 @@ depend on.
            Op  : Operation_Kind) return Natural;
      end Computer;
 
-  ::
+  .. code-block:: ada
 
      with Math;
      package body Computer is
@@ -520,7 +520,7 @@ depend on.
         end Compute;
      end Computer;
 
-  ::
+  .. code-block:: ada
 
      with Computer;
      pragma Elaborate_All (Computer);
@@ -738,7 +738,7 @@ execution. The warnings can be suppressed selectively with ``pragma Warnings
 A *guaranteed ABE* arises when the body of a target is not elaborated early
 enough, and causes *all* scenarios that directly invoke the target to fail.
 
-  ::
+  .. code-block:: ada
 
      package body Guaranteed_ABE is
         function ABE return Integer;
@@ -765,7 +765,7 @@ the declaration of ``Val``. This invokes function ``ABE``, however the body of
 A *conditional ABE* arises when the body of a target is not elaborated early
 enough, and causes *some* scenarios that directly invoke the target to fail.
 
-  ::
+  .. code-block:: ada
 
       1. package body Conditional_ABE is
       2.    procedure Force_Body is null;
@@ -850,19 +850,19 @@ clauses, elaboration-control pragmas, or invocations in elaboration code.
 
 The following example exhibits an elaboration circularity.
 
-  ::
+  .. code-block:: ada
 
      with B; pragma Elaborate (B);
      package A is
      end A;
 
-  ::
+  .. code-block:: ada
 
      package B is
         procedure Force_Body;
      end B;
 
-  ::
+  .. code-block:: ada
 
      with C;
      package body B is
@@ -871,13 +871,13 @@ The following example exhibits an elaboration circularity.
         Elab : constant Integer := C.Func;
      end B;
 
-  ::
+  .. code-block:: ada
 
      package C is
         function Func return Integer;
      end C;
 
-  ::
+  .. code-block:: ada
 
      with A;
      package body C is