Map various .NET file extensions to XML syntax

tests/syntax-tests/source/XML/Directory.Build.props

@@ -0,0 +1,5 @@
+<Project>
+   <PropertyGroup>
+      <OutDir>C:\output\$(MSBuildProjectName)</OutDir>
+   </PropertyGroup>
+</Project>

tests/syntax-tests/source/XML/console.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net9.0</TargetFramework>
+    <RootNamespace>SomeNamespace</RootNamespace>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

tests/syntax-tests/source/XML/projectname.targets

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+
+  <Target Name="TestTarget" AfterTargets="Build">
+    <Message Importance="High" Text="-------------MHM----------------" />
+  </Target>
+
+</Project>