Preserve Xunit test result XML
Preserve Xunit test result XML

This will allow the CI build to have nice displays for our test results,
as well as an overall pass/fail for the build script.

LordJZ/msbuild,LordJZ/msbuild,ValMenn/msbuild,rainersigwald/msbuild,AndyGerlicher/msbuild,mono/msbuild,Hyrtwol/msbuild,AndyGerlicher/msbuild,nikson/msbuild,sean-gilliam/msbuild,Microsoft/msbuild,cdmihai/msbuild,sean-gilliam/msbuild,EshG/msbuild,jeffkl/msbuild,chipitsine/msbuild,jeffkl/msbuild,ValMenn/msbuild,zima2219981998/msbuilding,chipitsine/msbuild,mono/msbuild,sean-gilliam/msbuild,yazeng/msbuild,mono/msbuild,nikson/msbuild,chipitsine/msbuild,rainersigwald/msbuild,ValMenn/msbuild,EshG/msbuild,nikson/msbuild,LordJZ/msbuild,jeffkl/msbuild,zima2219981998/msbuilding,Microsoft/msbuild,mono/msbuild,danteinforno/msbuild,yazeng/msbuild,zima2219981998/msbuilding,AndyGerlicher/msbuild,nikson/msbuild,yazeng/msbuild,EshG/msbuild,cdmihai/msbuild,oliver-feng/msbuild,Microsoft/msbuild,ValMenn/msbuild,danteinforno/msbuild,oliver-feng/msbuild,sean-gilliam/msbuild,rainersigwald/msbuild,Microsoft/msbuild,AndyGerlicher/msbuild,jeffkl/msbuild,Hyrtwol/msbuild,cdmihai/msbuild,chipitsine/msbuild,Hyrtwol/msbuild,cdmihai/msbuild,rainersigwald/msbuild,danteinforno/msbuild,oliver-feng/msbuild