ada: Disable Equivalent_Array_Aggregate optimization if predicates involved

ada: Disable Equivalent_Array_Aggregate optimization if predicates involved

In most paths, the function Build_Equivalent_Record_Aggregate was already
testing Has_Predicates for a given component type and conditionally returning
an Empty result. This is also needed in the case of a scalar component type.
Without it, we can build corrupt trees that fail use-before-definition
detection checks in gigi.

gcc/ada/

	* exp_ch3.adb (Build_Equivalent_Record_Aggregate): Add
	Has_Predicates test for a scalar component to match what is
	already done for other kinds of components.