Added performance microbenchmarks

- Added "Performance" folders containing perf xunit tests to a number of highly-used libraries (determined by Usage data)
- Two sets of usage data from store apps; I added a test for every function used in more than 5% of the covered assemblies in both data sets.
- This is a first-round pass of the most highly used libraries and does not include: abstract classes, interfaces, or Attributes
- Created a static utility class for commonly used functions across perf tests, stored in src\Common\tests\Performance.
- These tests will run using ```msbuild /t:BuildAndTest /p:performance=true``` from the projects test directory
- Added conditional properties that check if v5.0 is installed on the user's computer when running perf tests. If it isn't, a detailed error is thrown with a link to a performance-test github page that I've also added.

1 files changed, 15 insertions, 2 deletions

diff --git a/src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj b/src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj
index 49aec22928..9d4514cc27 100644
--- a/src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj
+++ b/src/System.IO.FileSystem/tests/System.IO.FileSystem.Tests.csproj
@@ -9,6 +9,11 @@
     <AssemblyName>System.IO.FileSystem.Tests</AssemblyName>
     <TestCategories>InnerLoop;OuterLoop</TestCategories>
   </PropertyGroup>
+  <!-- Performance tests require v5.0 portable tools -->
+  <PropertyGroup Condition="'$(RunPerfTestsForProject)' == 'true'">
+    <TargetFrameworkVersion>v5.0</TargetFrameworkVersion>
+    <TargetFrameworkProfile />
+  </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|AnyCPU'">
     <DebugSymbols>true</DebugSymbols>
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -28,7 +33,6 @@
       <Name>System.IO.FileSystem</Name>
       <Private>True</Private>
     </ProjectReference>
-
     <!-- 
       Until an updated packages is published, temporarily copy the locally built System.Runtime.Extensions library
       but still reference the contract from the package for compiling.  
@@ -165,5 +169,14 @@
       <Link>Common\System\IO\FileCleanupTestBase.cs</Link>
     </Compile>
   </ItemGroup>
+  <!-- Performance Tests -->
+  <ItemGroup Condition="'$(RunPerfTestsForProject)' == 'true'">
+    <Compile Include="Performance\Perf.Directory.cs" />
+    <Compile Include="Performance\Perf.File.cs" />
+    <Compile Include="Performance\Perf.FileInfo.cs" />
+    <Compile Include="$(CommonTestPath)\Performance\PerfUtils.cs">
+      <Link>Common\Performance\PerfUtils.cs</Link>
+    </Compile>
+  </ItemGroup>
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), dir.targets))\dir.targets" />
-</Project>
+</Project>
\ No newline at end of file