This is the build failure of the Ada runtime on SPARC64/Linux, caused by a 
miscompilation of the Ada front-end at -O2 or above.  The symptom is exactly 
the same as that of PR middle-end/44993, which was a similar build failure, 
although the root cause is slightly different.

It's delicate stuff in the middle-end so I'm applying a trivial workaround to 
the Ada front-end to unbreak the build and I'll create a testcase separately.

Boostrapped/regtested on SPARC64/Linux, applied on the mainline.


2017-06-12  Eric Botcazou  <ebotcazou@adacore.com>

	PR bootstrap/80897
	* exp_ch3.adb (Make_Predefined_Primitive_Specs): Use Positive index.

-- 
Eric Botcazou