Generate nonsemantic shader debug information

[tksuoran]

Proof of concept fix for #1391.

Possibly emitNonSemanticShaderDebugInfo and emitNonSemanticShaderDebugSource should be controlled using dedicated command line arguments instead of just -g.

This worked for me and allowed me to use RenderDoc source debugging.

[vinh-truong-sc]

Hey, we are also interested in this feature. Can someone look at this and merge it?

[dneto0]

The code is good.
The policy question is that when using -g the downstream tools and driver have to undertand non-semantic extended instruction sets. So in theory it's a backward incompatibility. But this is about debug info and it's being used in a development environment so it has to be deliberately turned on, and the remedy is easy: turn it back off.

So I think this is the right thing to do, even with the theoretical incompatibility.

[PolarNick239]

Hi! Debug information is very useful for Vulkan-API debugging with RenderDoc. I hope it will be merged soon! :)

[Trider12]

Why hasn't this been merged?

[dj2]

There are failing tests which need to be fixed up. The glslc_tests, and a bunch of the shaderc test suites all failed with the patch applied.