ada: Type error on container aggregate with loop_parameter_specification

ada: Type error on container aggregate with loop_parameter_specification

The compiler incorrectly reported a type error on a container aggregate
for a Vector type with a loop_parameter_specification specifying a
nonstatic upper bound, complaining that it expected the Vector index
type, but instead found type Count_Type. The expansion of the aggregate
was incorrectly passing a size temporary of type Count_Type to the
function associated with the New_Indexed part of the container type's
Aggregate aspect (New_Vector in the case of Vectors), which has two
formals of the container index type. The fix is to convert the size
temporary to the expected index type.

gcc/ada/

	* exp_aggr.adb (Expand_Container_Aggregate): Apply a conversion to the
	size temp object passed as the second actual parameter on the call to
	the New_Indexed_Subp function, to convert it to the index type of the
	container type (taken from the first formal parameter of the function).