If a GraphQLError represents multiple nodes across files (could happen for validation across multiple parsed files) then the reported locations and printError output can be incorrect for the second node. This ensures locations are derived from nodes whenever possible to get correct location and amends comment documentation.
ref: graphql/graphql-js#1131
A common case is encountering an error which blames to a single AST node. Ensure the GraphQLError constructor can handle this case.
ref: graphql/graphql-js#1123
