ArmPkg/ArmLib: AARCH64: allow the stack aligment (SA) bit to be managed

In preparation of enabling stack alignment checking, which is mandated
by the UEFI spec for AARCH64, add the code to manage this bit to ArmLib.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

ArmPkg/Include/Chipset/AArch64.h

@@ -192,6 +192,18 @@ ArmEnableAlignmentCheck (
   VOID
   );
 
+VOID
+EFIAPI
+ArmDisableStackAlignmentCheck (
+  VOID
+  );
+
+VOID
+EFIAPI
+ArmEnableStackAlignmentCheck (
+  VOID
+  );
+
 VOID
 EFIAPI
 ArmDisableAllExceptions (