ada: Crash initializing component of private record type

ada: Crash initializing component of private record type

The compiler may crash processing the full type declaration of a
private record type that initializes a component with a call to
a function instantiated in the private part of the package.

gcc/ada/

	* freeze.adb (Declared_In_Expanded_Body): New subprogram.
	(In_Expanded_Body): Minor code cleanup.
	(Freeze_Expression): Code cleanup plus factorize in a new function
	the code that identifies entities declared in the body of expander
	generated subprograms, since such case must be checked also for
	other node kinds when climbing the tree to locate the place to
	insert the freezing node.