MdePkg/BaseLib: BaseLib for LOONGARCH64 architecture.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4053

Add LoongArch LOONGARCH64 BaseLib functions.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>

Signed-off-by: Chao Li <lichao@loongson.cn>
Co-authored-by: Baoqi Zhang <zhangbaoqi@loongson.cn>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>

MdePkg/Library/BaseLib/LoongArch64/GetInterruptState.S

@@ -0,0 +1,35 @@
+#------------------------------------------------------------------------------
+#
+# Get LoongArch interrupt status
+#
+# Copyright (c) 2022, Loongson Technology Corporation Limited. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#------------------------------------------------------------------------------
+
+ASM_GLOBAL ASM_PFX(GetInterruptState)
+
+#/**
+#  Retrieves the current CPU interrupt state.
+#
+#  Returns TRUE means interrupts are currently enabled. Otherwise,
+#  returns FALSE.
+#
+#  @retval TRUE  CPU interrupts are enabled.
+#  @retval FALSE CPU interrupts are disabled.
+#
+#**/
+
+ASM_PFX(GetInterruptState):
+  li.w  $t1, 0x4
+  csrrd $t0, 0x0
+  and   $t0, $t0, $t1
+  beqz  $t0, 1f
+  li.w  $a0, 0x1
+  b     2f
+1:
+  li.w  $a0, 0x0
+2:
+  jirl  $zero, $ra, 0
+  .end