[Ada] Crash on interface equality covered by a renaming declaration

[Pierre-Marie de Rodat]

The frontend crashes processing a tagged type that implements an
interface which has an equality primitive (that is, "=") and covers such
primitive by means of a renaming declaration.

Tested on x86_64-pc-linux-gnu, committed on trunk

2018-11-14  Javier Miranda  <miranda@adacore.com>

gcc/ada/

	* exp_disp.adb (Expand_Interface_Thunk): Extend handling of
	renamings of the predefined equality primitive.
	(Make_Secondary_DT): When calling Expand_Interface_Thunk() pass
	it the primitive, instead of its Ultimate_Alias; required to
	allow the called routine to identify renamings of the predefined
	equality operation.

gcc/testsuite/

	* gnat.dg/equal5.adb, gnat.dg/equal5.ads: New testcase.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: patch.diff
Type: text/x-diff
Size: 3758 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20181114/e9b1f2a2/attachment.bin>