ada: Get rid of Sy/Sm mixing (Actions)

ada: Get rid of Sy/Sm mixing (Actions)

We should not mix "syntactic" and "semantic" for the same field
in different node kinds.

The Actions field is both syntactic and semantic. This patch
makes it always syntactic.

No change in overall compiler behavior.

gcc/ada/ChangeLog:

	* gen_il-gen.adb (N_Short_Circuit):
	Make Actions syntactic.
	(N_Case_Expression_Alternative): Likewise.
	* gen_il-gen-gen_nodes.adb (Create_Type):
	No longer exempt Actions from the syntactic/semantic ordering rule.
	(Check_For_Syntactic_Field_Mismatch):
	No longer exempt Actions from the syntactic/semantic mixing rule.
	* sinfo.ads (N_Compound_Statement):
	Add comment.