[Ada] Fix fallout of previous change for bit-packed arrays

This fixes a regression introduced by the previous change that improved
the handling of explicit by-reference mechanism. For the very specific
case of a component of a bit-packed array, the front-end still needs to
insert a copy around the call because this is where the rewriting into
the sequence of mask-and-shifts is done for the code generator.

2019-09-19  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* exp_ch6.adb (Add_Simple_Call_By_Copy_Code): Add
	Bit_Packed_Array parameter and documet it. Always insert a copy
	if it is set True.
	(Expand_Actuals): Adjust the calls to
	Add_Simple_Call_By_Copy_Code.

gcc/testsuite/

	* gnat.dg/pack26.adb: New testcase.

From-SVN: r275933

1 files changed, 23 insertions, 0 deletions

diff --git a/gcc/testsuite/gnat.dg/pack26.adb b/gcc/testsuite/gnat.dg/pack26.adb
new file mode 100644
index 0000000..6365296
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/pack26.adb
@@ -0,0 +1,23 @@
+--  { dg-do run }
+
+pragma Extend_System (Aux_DEC);
+
+with System;
+
+procedure Pack26 is
+
+  type Bool_Array is array (1 .. 8) of Boolean;
+  pragma pack (Bool_Array);
+
+  All_True : Bool_Array := (others => True);
+  Old_Value : Boolean := False;
+
+begin
+
+  System.Clear_Interlocked (All_True (2), Old_Value);
+
+  if not Old_Value then
+    raise Program_Error;
+  end if;
+
+end;
\ No newline at end of file