Optimise glob construction when single item
Optimise glob construction when single item

In cases where a single item exists, avoid allocation of an enumerable and enumerator and construct the glob directly.

AndyGerlicher/msbuild,AndyGerlicher/msbuild,sean-gilliam/msbuild,rainersigwald/msbuild,sean-gilliam/msbuild,AndyGerlicher/msbuild,rainersigwald/msbuild,sean-gilliam/msbuild,sean-gilliam/msbuild,AndyGerlicher/msbuild,rainersigwald/msbuild,rainersigwald/msbuild