[Ada] Spurious error on read of out parameter in Ada_83 mode

[Pierre-Marie de Rodat <derodat at adacore dot com>]

This patch fixes a regression in the handling of out parameters that appear
as the prefix of an attribute, when compiling in Ada_83 mode. Such implicit
read operations are legal in Ada_83 when the parameter is of an array type
and the attribute yields bound information.

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

gcc/ada/

2017-11-09  Ed Schonberg  <schonberg@adacore.com>

	* exp_ch3.adb, gnat1drv.adb, namet.adb, namet.ads, sem_aggr.adb,
	sem_ch2.adb, sem_ch4.adb: Minor reformatting.
	* sem_res.adb (Resolve_Entity_Name): Suppress spurious error on read of
	out parameter when in Ada_83 mode, the oarameter is of a composite
	type, and it appears as the prefix of an attribute.

gcc/testsuite/

2017-11-09  Ed Schonberg  <schonberg@adacore.com>

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

Attachment: difs
Description: Text document