sem_intr.adb: (Check_Shift): Diagnose bad modulus value.

2015-05-12  Robert Dewar  <dewar@adacore.com>

	* sem_intr.adb: (Check_Shift): Diagnose bad modulus value.

2015-05-12  Robert Dewar  <dewar@adacore.com>

	* gnat1drv.adb (Adjust_Global_Switches): Default to suppressing
	Alignment_Checks on non-strict alignment machine.
	* sem_ch13.adb (Validate_Address_Clauses): Don't give
	compile-time alignment warnings if run time Alignment_Check
	is suppressed.

From-SVN: r223063