Trouble building on windows

I've recently downloaded the most recent vulkan SDK, and have updated to build the included shaderc there.

spirv-tools-spv-amd-shader-explicit-vertex-parameter

```
5>------ Build started: Project: spirv-tools-spv-amd-shader-explicit-vertex-parameter, Configuration: RelWithDebInfo x64 ------
5>C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VC\v160\Microsoft.CppBuild.targets(321,5): error MSB3491: Could not write lines to file "x64\RelWithDebInfo\spirv-tools-spv-amd-shader-explicit-vertex-parameter\spirv-to.D405BAD2.tlog\spirv-tools-spv-amd-shader-explicit-vertex-parameter.lastbuildstate". Path: x64\RelWithDebInfo\spirv-tools-spv-amd-shader-explicit-vertex-parameter\spirv-to.D405BAD2.tlog\spirv-tools-spv-amd-shader-explicit-vertex-parameter.lastbuildstate exceeds the OS max path limit. The fully qualified file name must be less than 260 characters.
```

I guess I have it kinda deep already to build

```
163
x64\RelWithDebInfo\spirv-tools-spv-amd-shader-explicit-vertex-parameter\spirv-to.D405BAD2.tlog\spirv-tools-spv-amd-shader-explicit-vertex-parameter.lastbuildstate

67
H:\build\sack-vs15\RelWithDebInfo_solution\core\src\imglib\vulkan\
40
shaderc\third_party\spirv-tools\source\

270 total characters from the above...

(above path parts from ... which is about where it builds)
H:\build\sack-vs15\RelWithDebInfo_solution\core\src\imglib\vulkan\shaderc\third_party\spirv-tools\source\spirv-tools-spv-amd-shader-explicit-vertex-parameter.vcxproj
```

I appreciate long project names like
`spirv-tools-spv-amd-shader-explicit-vertex-parameter`
but there are problems with those... ahh I see; really that's just the name of a JSON file, turned into an include...