spirv: Handle ShaderLayer and ShaderViewportIndex capabilities

SPIR-V 1.5 incorported the SPV_EXT_shader_viewport_index_layer but
splitting into the two capabilities above.  Just handle them as we
support the extension already.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/compiler/spirv/spirv_to_nir.c

@@ -3573,6 +3573,8 @@ vtn_handle_preamble_instruction(struct vtn_builder *b, SpvOp opcode,
          spv_check_supported(storage_16bit, cap);
          break;
 
+      case SpvCapabilityShaderLayer:
+      case SpvCapabilityShaderViewportIndex:
       case SpvCapabilityShaderViewportIndexLayerEXT:
          spv_check_supported(shader_viewport_index_layer, cap);
          break;