[Ada] Spurious visibility error in inlined function

This patch corrects the use of tree replication when inlining a function
that returns an unconstrained result, and its sole statement is an
extended return statement. The use of New_Copy_Tree ensires that global
references saved in a generic template are properly carried over when
the function is instantiated and inlined.

2019-07-03  Hristian Kirtchev  <kirtchev@adacore.com>

gcc/ada/

	* inline.adb (Build_Return_Object_Formal): New routine.
	(Can_Split_Unconstrained_Function): Code clean up.
	(Copy_Formals,Copy_Return_Object): New routines.
	(Split_Unconstrained_Function): Code clean up and refactoring.

gcc/testsuite/

	* gnat.dg/inline15.adb, gnat.dg/inline15_gen.adb,
	gnat.dg/inline15_gen.ads, gnat.dg/inline15_types.ads: New
	testcase.

From-SVN: r272980

gcc/ada/ChangeLog

+2019-07-03  Hristian Kirtchev  <kirtchev@adacore.com>
+
+	* inline.adb (Build_Return_Object_Formal): New routine.
+	(Can_Split_Unconstrained_Function): Code clean up.
+	(Copy_Formals,Copy_Return_Object): New routines.
+	(Split_Unconstrained_Function): Code clean up and refactoring.
+
 2019-07-03  Gary Dismukes  <dismukes@adacore.com>
 
 	* bindo-augmentors.adb, bindo-augmentors.ads,

gcc/testsuite/ChangeLog

+2019-07-03  Hristian Kirtchev  <kirtchev@adacore.com>
+
+	* gnat.dg/inline15.adb, gnat.dg/inline15_gen.adb,
+	gnat.dg/inline15_gen.ads, gnat.dg/inline15_types.ads: New
+	testcase.
+
 2019-07-03  Bob Duff  <duff@adacore.com>
 
 	* gnat.dg/warn20.adb, gnat.dg/warn20_pkg.adb,

gcc/testsuite/gnat.dg/inline15.adb

+--  { dg-do compile }
+--  { dg-options "-O2" }
+
+with Inline15_Gen;
+
+procedure Inline15 is
+   package Inst is new Inline15_Gen;
+
+begin
+   Inst.Call_Func;
+end Inline15;

gcc/testsuite/gnat.dg/inline15_gen.adb

+package body Inline15_Gen is
+   function Initialize (Val : Inline15_Types.Enum) return Inline15_Types.Rec;
+   procedure Print (Val : Inline15_Types.Rec);
+
+   procedure Call_Func is
+      Result : constant Inline15_Types.Rec := Func (Inline15_Types.Two);
+   begin
+      null;
+   end Call_Func;
+
+   function Func (Val : Inline15_Types.Enum) return Inline15_Types.Rec is
+   begin
+      return Result : constant Inline15_Types.Rec := Initialize (Val) do
+         Print (Result);
+      end return;
+   end Func;
+
+   function Initialize (Val : Inline15_Types.Enum) return Inline15_Types.Rec is
+      pragma Warnings (Off);
+      Result : Inline15_Types.Rec (Val);
+      pragma Warnings (On);
+   begin
+      return Result;
+   end Initialize;
+
+   procedure Print (Val : Inline15_Types.Rec) is begin null; end Print;
+end Inline15_Gen;

gcc/testsuite/gnat.dg/inline15_gen.ads

+
+--  gen.ads
+
+with Inline15_Types;
+
+generic
+package Inline15_Gen is
+   function Func (Val : Inline15_Types.Enum) return Inline15_Types.Rec with Inline;
+
+   procedure Call_Func with Inline;
+end Inline15_Gen;

gcc/testsuite/gnat.dg/inline15_types.ads

+package Inline15_Types is
+   type Enum is (One, Two, Three, Four);
+
+   type Rec (Discr : Enum) is record
+      Comp_1 : Integer;
+
+      case Discr is
+         when One =>
+            Comp_2 : Float;
+         when Two =>
+            Comp_3 : Boolean;
+            Comp_4 : Long_Float;
+         when others =>
+            null;
+      end case;
+   end record;
+end Inline15_Types;