Add support for specifying the logical SPIR-V target environment in the triple as Vulkan. When compiling HLSL, this replaces the DirectX Shader Model with a Vulkan environment instead. Currently, the only supported combinations of SPIR-V version and Vulkan environment are: - Vulkan 1.2 and SPIR-V 1.5 - Vulkan 1.3 and SPIR-V 1.6 Fixes #70051