Be mindful of the version of spirv-tools that this links to. Upstream actually expects the use of the particular commits of spirv-tools and spirv-headers that are provided in the DEPS file.
However, if we went that route, we'd have to vendor the resulting spirv-tools libs from this shaderc build and they would be incompatible with system libs, resulting in us having to ship both. Instead, I recommend just waiting until upstream releases a compatible version of spirv-tools, then updating the spriv-tools system package and only then building shaderc against that.