[Ada] Record components do not appear in the Global contract

[Ada] Record components do not appear in the Global contract

In the Global contract there can be only entire objects, which are
represented either as N_Identifier or N_Expanded_Name. The test for
record components was dead. Now removed. Semantics unaffected.

2018-11-14  Piotr Trojanek  <trojanek@adacore.com>

gcc/ada/

	* sem_util.adb (First_From_Global_List): Do not expect
	N_Selected_Component in the Global contract; simplify assertion
	with Nam_In.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@266113 138bc75d-0d04-0410-961f-82ee72b054a4