Merge pull request #2620 from JeremyKuhne/UnixPath

When building other platforms, skip tests

Author: stephentoub

dir.props

@@ -235,6 +235,11 @@
     <TargetsUnix Condition="'$(TargetsLinux)' == 'true' or '$(TargetsOSX)' == 'true' or '$(TargetsFreeBSD)' == 'true'">true</TargetsUnix>
   </PropertyGroup>
 
+  <PropertyGroup>
+    <!-- Don't run tests if we're building another platform's binaries on Windows -->
+    <SkipTests Condition="'$(SkipTests)'=='' and ('$(OsEnvironment)'=='Windows_NT' and '$(TargetsWindows)'!='true')">true</SkipTests>
+  </PropertyGroup>
+
   <PropertyGroup>
     <!-- Work around known Dev14 bug - see
          https://connect.microsoft.com/VisualStudio/feedback/details/1000796/connect-file-uap-props-not-found-cant-build-a-portable-lib-on-vs14