[Ada] Suppress Initialize_Scalars for Persistent_BSS

[Ada] Suppress Initialize_Scalars for Persistent_BSS

If a variable has pragma Persistent_BSS, the compiler now automatically
suppresses implicit initializations caused by Initialize_Scalars and
Normalize_Scalars. Variables with Persistent_BSS cannot be initialized,
and previously a pragma Suppress_Initialization was required before the
pragma Persistent_BSS.

2019-08-20  Bob Duff  <duff@adacore.com>

gcc/ada/

	* sem_prag.adb (Persistent_BSS): If an initialization is present
	because of Initialize_Scalars or Normalize_Scalars, generate an
	implicit pragma Suppress_Initialization to remove that, because
	initialization is not allowed for these variables. Other
	initializations remain illegal.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@274732 138bc75d-0d04-0410-961f-82ee72b054a4