MdePkg/Library/BaseLib: Enable VS2017/ARM64 builds

Required GCC assembly files are converted for the MSFT assembler

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Pete Batard <pete@akeo.ie>
Reviewed-by: Liming Gao <liming.gao@intel.com>

MdePkg/Library/BaseLib/AArch64/GetInterruptsState.asm

@@ -0,0 +1,49 @@
+;------------------------------------------------------------------------------
+;
+; GetInterruptState() function for AArch64
+;
+; Copyright (c) 2006 - 2009, Intel Corporation. All rights reserved.<BR>
+; Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
+; Portions copyright (c) 2011 - 2013, ARM Ltd. All rights reserved.<BR>
+; This program and the accompanying materials
+; are licensed and made available under the terms and conditions of the BSD License
+; which accompanies this distribution.  The full text of the license may be found at
+; http://opensource.org/licenses/bsd-license.php.
+;
+; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+;
+;------------------------------------------------------------------------------
+
+  EXPORT GetInterruptState
+  AREA BaseLib_LowLevel, CODE, READONLY
+
+DAIF_RD_IRQ_BIT     EQU     (1 << 7)
+
+;/**
+;  Retrieves the current CPU interrupt state.
+;
+;  Returns TRUE is interrupts are currently enabled. Otherwise
+;  returns FALSE.
+;
+;  @retval TRUE  CPU interrupts are enabled.
+;  @retval FALSE CPU interrupts are disabled.
+;
+;**/
+;
+;BOOLEAN
+;EFIAPI
+;GetInterruptState (
+;  VOID
+; );
+;
+GetInterruptState
+    mrs    x0, daif
+    mov    w0, wzr
+    tst    x0, #DAIF_RD_IRQ_BIT   // Check IRQ mask; set Z=1 if clear/unmasked
+    bne    exit                   // if Z=1 (eq) return 1, else 0
+    mov    w0, #1
+exit
+    ret
+
+  END