As of Visual Studio 2015 CTP5 the Roslyn cache and suo files are stored in a .vs/ directory.
@@ -25,6 +25,9 @@ bld/
# Roslyn cache directories
*.ide/
+# Visual Studo 2015 cache/options directory
+.vs/
+
# MSTest test Results
[Tt]est[Rr]esult*/
[Bb]uild[Ll]og.*
Emil Lerch