MdePkg/Test: Add SafeIntLib and BaseLib Base64 unit tests

https://bugzilla.tianocore.org/show_bug.cgi?id=2505

* Add unit tests for SafeIntLib class
* Add unit tests for BaseLib Base64 conversion APIs.
* Add Test/MdePkgHostTest.dsc -to build host based unit
  tests
* Update MdePkg.dsc to build target based tests for
  SafeIntLib and BaseLib
* Update MdePkg.ci.yaml to build and run host based
  tests for SafeIntLib and BaseLib

Cc: Sean Brogan <sean.brogan@microsoft.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Cc: Liming Gao <liming.gao@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Acked-by: Hao A Wu <hao.a.wu@intel.com>
Reviewed-by: Bret Barkelew <Bret.Barkelew@microsoft.com>

MdePkg/Test/UnitTest/Library/BaseSafeIntLib/TestBaseSafeIntLib.h

@@ -0,0 +1,123 @@
+/** @file
+  UEFI OS based application for unit testing the SafeIntLib.
+
+  Copyright (c) Microsoft Corporation.<BR>
+  Copyright (c) 2018 - 2020, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef _TEST_BASE_SAFE_INT_LIB_H_
+#define _TEST_BASE_SAFE_INT_LIB_H_
+
+#include <PiPei.h>
+#include <Uefi.h>
+#include <Library/UefiLib.h>
+#include <Library/DebugLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UnitTestLib.h>
+#include <Library/SafeIntLib.h>
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeInt32ToUintn(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeUint32ToIntn(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeIntnToInt32(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeIntnToUint32(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeUintnToUint32(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeUintnToIntn(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeUintnToInt64(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeInt64ToIntn(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeInt64ToUintn(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeUint64ToIntn(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeUint64ToUintn(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeUintnAdd(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeIntnAdd(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeUintnSub(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeIntnSub(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeUintnMult(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+UNIT_TEST_STATUS
+EFIAPI
+TestSafeIntnMult(
+  IN UNIT_TEST_CONTEXT           Context
+  );
+
+#endif