Create Mock for PostCodeLib (#1168)

## Description

Create Mock for PostCodeLib

For details on how to complete these options and their meaning refer to
[CONTRIBUTING.md](https://github.com/microsoft/mu/blob/HEAD/CONTRIBUTING.md).

- [ ] Impacts functionality?
- [ ] Impacts security?
- [ ] Breaking change?
- [ ] Includes tests?
- [ ] Includes documentation?
- [x] Backport to release branch?

## How This Was Tested

Unit tests component can call these mock functions success

## Integration Instructions

N/A

MdePkg/Test/MdePkgHostTest.dsc

@@ -70,4 +70,5 @@
   MdePkg/Test/Mock/Library/GoogleTest/MockCpuLib/MockCpuLib.inf
   MdePkg/Test/Mock/Library/GoogleTest/MockPciSegmentLib/MockPciSegmentLib.inf
   MdePkg/Test/Mock/Library/GoogleTest/MockReportStatusCodeLib/MockReportStatusCodeLib.inf
+  MdePkg/Test/Mock/Library/GoogleTest/MockPostCodeLib/MockPostCodeLib.inf
   # MU_CHANGE [END]

MdePkg/Test/Mock/Include/GoogleTest/Library/MockPostCodeLib.h

@@ -0,0 +1,55 @@
+/** @file MockPostCodeLib.h
+  Google Test mocks for PostCodeLib
+
+  Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
+  Copyright (c) Microsoft Corporation.
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#ifndef MOCK_POST_CODE_LIB_H_
+#define MOCK_POST_CODE_LIB_H_
+
+#include <Library/GoogleTestLib.h>
+#include <Library/FunctionMockLib.h>
+extern "C" {
+  #include <Uefi.h>
+  #include <Library/PostCodeLib.h>
+}
+
+struct MockPostCodeLib {
+  MOCK_INTERFACE_DECLARATION (MockPostCodeLib);
+
+  MOCK_FUNCTION_DECLARATION (
+    UINT32,
+    PostCode,
+    (
+     IN UINT32  Value
+    )
+    );
+  MOCK_FUNCTION_DECLARATION (
+    UINT32,
+    PostCodeWithDescription,
+    (
+     IN UINT32       Value,
+     IN CONST CHAR8  *Description  OPTIONAL
+    )
+    );
+
+  MOCK_FUNCTION_DECLARATION (
+    BOOLEAN,
+    PostCodeEnabled,
+    (
+
+    )
+    );
+
+  MOCK_FUNCTION_DECLARATION (
+    BOOLEAN,
+    PostCodeDescriptionEnabled,
+    (
+
+    )
+    );
+};
+
+#endif //MOCK_PCI_EXPRESS_LIB_H_

MdePkg/Test/Mock/Library/GoogleTest/MockPostCodeLib/MockPostCodeLib.cpp

@@ -0,0 +1,14 @@
+/** @file MockPostCodeLib.cpp
+  Google Test mocks for PostCodeLib
+
+  Copyright (c) Microsoft Corporation.
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <GoogleTest/Library/MockPostCodeLib.h>
+
+MOCK_INTERFACE_DEFINITION (MockPostCodeLib);
+MOCK_FUNCTION_DEFINITION (MockPostCodeLib, PostCode, 1, EFIAPI);
+MOCK_FUNCTION_DEFINITION (MockPostCodeLib, PostCodeWithDescription, 2, EFIAPI);
+MOCK_FUNCTION_DEFINITION (MockPostCodeLib, PostCodeEnabled, 0, EFIAPI);
+MOCK_FUNCTION_DEFINITION (MockPostCodeLib, PostCodeDescriptionEnabled, 0, EFIAPI);

MdePkg/Test/Mock/Library/GoogleTest/MockPostCodeLib/MockPostCodeLib.inf

@@ -0,0 +1,33 @@
+## @file MockPostCodeLib.inf
+# Google Test mocks for PostCodeLib
+#
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = MockPostCodeLib
+  FILE_GUID                      = 25BF192B-A519-4997-823A-AFEC2C953627
+  MODULE_TYPE                    = HOST_APPLICATION
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = PostCodeLib
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+#  VALID_ARCHITECTURES           = IA32 X64
+#
+
+[Sources]
+  MockPostCodeLib.cpp
+
+[Packages]
+  MdePkg/MdePkg.dec
+  UnitTestFrameworkPkg/UnitTestFrameworkPkg.dec
+
+[LibraryClasses]
+  GoogleTestLib
+
+[BuildOptions]
+  MSFT:*_*_*_CC_FLAGS = /EHsc