ada: Simplify check for type without stream operations

ada: Simplify check for type without stream operations

Recursive routine Type_Without_Stream_Operation was checking restriction
No_Default_Stream_Attributes at every call, which was confusing and
inefficient.

This routine is only called from the places: Check_Stream_Attribute,
which already checks if this restriction is active, and
Stream_Operation_OK, where we add such a check.

Cleanup related to extending the use of No_Streams restriction.

gcc/ada/

	* exp_ch3.adb (Stream_Operation_OK): Check restriction
	No_Default_Stream_Attributes before call to
	Type_Without_Stream_Operation.
	* sem_util.adb (Type_Without_Stream_Operation): Remove static
	condition from recursive routine