ArmPkg: Ensured the stack is always quad-word aligned

From the AArch64 Procedure Call Standard (ARM IHI 0055B):

  5.2.2.1 Universal stack constraints
  At all times the following basic constraints must hold:
  - SP mod 16 = 0. The stack must be quad-word aligned.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16327 6f19259b-4bc3-4df7-8a09-765794883524
3 files changed