ada: Delay expansion of iterated component association

ada: Delay expansion of iterated component association

When preanalysing spec expression (e.g. expression of an expression
function), the name of iterator specification within an iterated
component association should not be expanded, especially in GNATprove
mode.

gcc/ada/

	* sem_ch5.adb (Analyze_Iterator_Specification): Delay expansion of
	for iterated component association just like it is done within
	quantified expression.