microsoft/compiler: Add dedicated spirv_to_dxil libraries

Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8043>

meson_options.txt

@@ -289,6 +289,12 @@ option(
   value : 'auto',
   description : 'Build support for the Microsoft CLC to DXIL compiler'
 )
+option(
+  'spirv-to-dxil',
+  type : 'boolean',
+  value : false,
+  description : 'Build support for the SPIR-V to DXIL library'
+)
 option(
   'glvnd-vendor-name',
   type : 'string',