2015-10-26  Hristian Kirtchev  <kirtchev@adacore.com>

	* exp_ch4.adb (Is_OK_Object_Reference): New routine.
	(Substitute_Valid_Check): Perform the 'Valid subsitution but do
	not suggest the use of the attribute if the left hand operand
	does not denote an object as it leads to illegal code.

2015-10-26  Hristian Kirtchev  <kirtchev@adacore.com>

	* exp_unst.adb: Minor reformatting.

2015-10-26  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch6.adb: Improve error msg.

From-SVN: r229341