paperchalice

Just upgrade glfw to the version which higher than 3.3.

`qt` with vulkan support in fact doesn't contain the `molten-vk` linkage, so mark it as build dependency and introduce build dependency `vulkan-headers` is enough, and the extra cmake flags are...

> But there are no virtual methods, so are we removing distinct phases (like `addPreEmitPasses()`) completely and only using `injectBefore()` now? IMHO some phases here is not clear, the example...

Ping @aeubanks @arsenm

Support dummy injection points now, they are PreISel, PostBBSections and PreEmit.

ping @aeubanks

Ping? @aeubanks

> If I understand correctly, the idea in this patch is that TargetPassBuilder mimics the interface of PassBuilder, but doesn't build the final structure of PassManagers yet. Instead it stores...

> What exactly do you consider the hack here? The logic in `constructRealPassManager()` with respect to the explicit nesting requirement? Or do you mean the hijacking of the pass-managers for...

Now CodeGen part are using pass managers with `Target` prefix.