Help: Remove unnecessary Sphinx versionadded markup in VS toolset selection

In a document that says "New in version 3.14", we do not need any blocks
that say "New in version 3.8".

Help/generator/VS_TOOLSET_HOST_ARCH.txt

@@ -1,11 +1,7 @@
-.. versionadded:: 3.8
-  For each toolset that comes with this version of Visual Studio, there are
-  variants that are themselves compiled for 32-bit (``x86``) and
-  64-bit (``x64``) hosts (independent of the architecture they target).
-  |VS_TOOLSET_HOST_ARCH_DEFAULT|
-  One may explicitly request use of either the 32-bit or 64-bit host tools
-  by adding either ``host=x86`` or ``host=x64`` to the toolset specification.
-  See the :variable:`CMAKE_GENERATOR_TOOLSET` variable for details.
-
-.. versionadded:: 3.14
-  Added support for ``host=x86`` option.
+For each toolset that comes with this version of Visual Studio, there are
+variants that are themselves compiled for 32-bit (``x86``) and
+64-bit (``x64``) hosts (independent of the architecture they target).
+|VS_TOOLSET_HOST_ARCH_DEFAULT|
+One may explicitly request use of either the 32-bit or 64-bit host tools
+by adding either ``host=x86`` or ``host=x64`` to the toolset specification.
+See the :variable:`CMAKE_GENERATOR_TOOLSET` variable for details.

Help/generator/VS_TOOLSET_HOST_ARCH_LEGACY.txt

@@ -0,0 +1,11 @@
+.. versionadded:: 3.8
+  For each toolset that comes with this version of Visual Studio, there are
+  variants that are themselves compiled for 32-bit (``x86``) and
+  64-bit (``x64``) hosts (independent of the architecture they target).
+  |VS_TOOLSET_HOST_ARCH_DEFAULT|
+  One may explicitly request use of either the 32-bit or 64-bit host tools
+  by adding either ``host=x86`` or ``host=x64`` to the toolset specification.
+  See the :variable:`CMAKE_GENERATOR_TOOLSET` variable for details.
+
+.. versionadded:: 3.14
+  Added support for ``host=x86`` option.

Help/generator/Visual Studio 12 2013.rst

@@ -46,4 +46,4 @@ via the :manual:`cmake(1)` ``-T`` option, to specify another toolset.
 .. |VS_TOOLSET_HOST_ARCH_DEFAULT| replace::
    By default this generator uses the 32-bit variant even on a 64-bit host.
 
-.. include:: VS_TOOLSET_HOST_ARCH.txt
+.. include:: VS_TOOLSET_HOST_ARCH_LEGACY.txt

Help/generator/Visual Studio 14 2015.rst

@@ -44,7 +44,7 @@ via the :manual:`cmake(1)` ``-T`` option, to specify another toolset.
 .. |VS_TOOLSET_HOST_ARCH_DEFAULT| replace::
    By default this generator uses the 32-bit variant even on a 64-bit host.
 
-.. include:: VS_TOOLSET_HOST_ARCH.txt
+.. include:: VS_TOOLSET_HOST_ARCH_LEGACY.txt
 
 .. _`Windows 10 SDK Maximum Version for VS 2015`:
 

Help/generator/Visual Studio 15 2017.rst

@@ -63,4 +63,4 @@ via the :manual:`cmake(1)` ``-T`` option, to specify another toolset.
 .. |VS_TOOLSET_HOST_ARCH_DEFAULT| replace::
    By default this generator uses the 32-bit variant even on a 64-bit host.
 
-.. include:: VS_TOOLSET_HOST_ARCH.txt
+.. include:: VS_TOOLSET_HOST_ARCH_LEGACY.txt