Help: Document Nsight Tegra toolchain configuration (#15276)

Help/manual/cmake-toolchains.7.rst

@@ -241,3 +241,20 @@ Windows Store may look like this:
 
   set(CMAKE_SYSTEM_NAME WindowsStore)
   set(CMAKE_SYSTEM_VERSION 8.1)
+
+Cross Compiling using NVIDIA Nsight Tegra
+-----------------------------------------
+
+A toolchain file to configure a Visual Studio generator to
+build using NVIDIA Nsight Tegra targeting Android may look
+like this:
+
+.. code-block:: cmake
+
+  set(CMAKE_SYSTEM_NAME Android)
+
+The :variable:`CMAKE_GENERATOR_TOOLSET` may be set to select
+the Nsight Tegra "Toolchain Version" value.
+
+See the :prop_tgt:`ANDROID_API` and :prop_tgt:`ANDROID_GUI`
+target properties to configure targets within the project.

Help/prop_tgt/ANDROID_GUI.rst

@@ -7,3 +7,7 @@ When this property is set to true the executable when built for Android
 will be created as an application package.  This property is initialized
 by the value of the :variable:`CMAKE_ANDROID_GUI` variable if it is set
 when a target is created.
+
+Add the ``AndroidManifest.xml`` source file explicitly to the
+target :command:`add_executable` command invocation to specify the
+root directory of the application package source.