Instruction that spans multiple lines with an escaped newline at the beginning of the line will throw an error

[rcjsuen]

RUN \
"\
\
"

Definitely a rather obscure Dockerfile but looks like our parser is unable to handle it.

import { DockerfileParser } from 'dockerfile-ast';
let dockerfile = DockerfileParser.parse(
    "RUN \\\n" +
    "\"\\\n" +
    "\\\n" +
    "\""
);
let instruction = dockerfile.getInstructions()[0];
console.log(instruction.getArgumentsContent());

.../node_modules/vscode-languageserver-types/lib/umd/main.js:54
                throw new Error("Range#create called with invalid arguments[" + one + ", " + two + ", " + three + ", " + four + "]");
                ^

Error: Range#create called with invalid arguments[null, [object Object], undefined, undefined]
    at Object.create (.../node_modules/vscode-languageserver-types/lib/umd/main.js:54:23)
    at JSONInstruction.getArgumentsRanges (.../out/src/instruction.js:101:69)
    at JSONInstruction.getArgumentsContent (.../out/src/instruction.js:159:27)
    at Object.<anonymous> (.../out/src/test.js:9:25)
    at Module._compile (internal/modules/cjs/loader.js:778:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10)
    at Module.load (internal/modules/cjs/loader.js:653:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
    at Function.Module._load (internal/modules/cjs/loader.js:585:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:831:12)