Xcode: Add schemes: GPU Validation & default build configuration
Add Xcode Scheme properties:
XCODE_SCHEME_ENABLE_GPU_API_VALIDATIONXCODE_SCHEME_ENABLE_GPU_SHADER_VALIDATIONXCODE_SCHEME_LAUNCH_CONFIGURATION
Edited by Brad King
Add Xcode Scheme properties:
XCODE_SCHEME_ENABLE_GPU_API_VALIDATIONXCODE_SCHEME_ENABLE_GPU_SHADER_VALIDATIONXCODE_SCHEME_LAUNCH_CONFIGURATION