hasBuiltin( name, shaderStage = this.shaderStage ) {

		return ( this.builtins[ shaderStage ] !== undefined && this.builtins[ shaderStage ].has( name ) );

	}
Returns `true` if the given builtin is defined in the given shader stage.

@param {string} name - The builtin name.
@param {string} [shaderStage=this.shaderStage] - The shader stage this code snippet is generated for.
@return {boolean} Whether the given builtin is defined in the given shader stage or not.