Regression: generated msvc solution contains no inter-project dependencies

If one project refers to another project's build product in its LIBS variable, then the generated MSVC .sln file should include a ProjectSection(ProjectDependencies), but doesn't. This can result in the dependent project being potentially built before its dependency, which will cause a linker error.

Attached is a minimal example which demonstrates the problem, and the solution files which are generated when I run qmake -r -tp vc with Qt 5.4.1 (good) and Qt 5.6 Beta snapshot 268 (bad). I haven't tested with Qt 5.5 but I presume if nobody complained about it before that the bug can't have been in any stable release. I also couldn't test with Qt 5.6 Alpha. Qt 5.6 Beta snapshot 198 does exhibit the same bug.