[Ada] Crash on inherited private operation in child package

[Ada] Crash on inherited private operation in child package

2019-12-13  Ed Schonberg  <schonberg@adacore.com>

gcc/ada/

	* sem_ch7.adb (Analyze_Package_Body_Helper): Do not call
	Declare_Inherited_Private_Subprograms on s child body: the
	required operations have already been created when analyzing the
	corresponding package declaration. This prevents a redeclaration
	of inehrited operation, and a crash when inserting the new
	operation in the current scope.

From-SVN: r279349