Added submodule contents into tree

externals/mbedtls/programs/test/cmake_package/.gitignore

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+build
+Makefile
+cmake_package

externals/mbedtls/programs/test/cmake_package/CMakeLists.txt

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+cmake_minimum_required(VERSION 3.5.1)
+
+#
+# Simulate configuring and building Mbed TLS as the user might do it. We'll
+# skip installing it, and use the build directory directly instead.
+#
+
+set(MbedTLS_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../../..")
+set(MbedTLS_BINARY_DIR "${CMAKE_CURRENT_BINARY_DIR}/mbedtls")
+
+execute_process(
+    COMMAND "${CMAKE_COMMAND}"
+        "-H${MbedTLS_SOURCE_DIR}"
+        "-B${MbedTLS_BINARY_DIR}"
+        "-DENABLE_PROGRAMS=NO"
+        "-DENABLE_TESTING=NO"
+        # Turn on generated files explicitly in case this is a release
+        "-DGEN_FILES=ON")
+
+execute_process(
+    COMMAND "${CMAKE_COMMAND}"
+        --build "${MbedTLS_BINARY_DIR}")
+
+#
+# Locate the package.
+#
+
+set(MbedTLS_DIR "${MbedTLS_BINARY_DIR}/cmake")
+find_package(MbedTLS REQUIRED)
+
+#
+# At this point, the Mbed TLS targets should have been imported, and we can now
+# link to them from our own program.
+#
+
+add_executable(cmake_package cmake_package.c)
+target_link_libraries(cmake_package
+    MbedTLS::mbedcrypto MbedTLS::mbedtls MbedTLS::mbedx509)

externals/mbedtls/programs/test/cmake_package/cmake_package.c

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+/*
+ *  Simple program to test that Mbed TLS builds correctly as a CMake package.
+ *
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ */
+
+#include "mbedtls/build_info.h"
+
+#include "mbedtls/platform.h"
+
+#include "mbedtls/version.h"
+
+/* The main reason to build this is for testing the CMake build, so the program
+ * doesn't need to do very much. It calls a single library function to ensure
+ * linkage works, but that is all. */
+int main()
+{
+    /* This version string is 18 bytes long, as advised by version.h. */
+    char version[18];
+
+    mbedtls_version_get_string_full(version);
+
+    mbedtls_printf("Built against %s\n", version);
+
+    return 0;
+}