Generate source map from esprima tokens

[yuya-takeyama]

Currently it can't generate source map without input source map.
So it can show wrong stack traces.

I added generateSourceMapFromTokens and it generate source map from tokens using esprima.

How to test

With v1.1.0

$ git checkout https://github.com/yuya-takeyama/strict-loader-test
$ yarn
$ yarn start
...
/Users/yuya/src/github.com/yuya-takeyama/strict-loader-test/foo.js:9
    throw new Error('Fail');
^
Error: Fail
    at bar (/Users/yuya/src/github.com/yuya-takeyama/strict-loader-test/foo.js:9:1)
    at foo (/Users/yuya/src/github.com/yuya-takeyama/strict-loader-test/foo.js:4:1)
    at Object.<anonymous> (/Users/yuya/src/github.com/yuya-takeyama/strict-loader-test/index.js:7:1)
...
error Command failed with exit code 1.

With this patch

$ git checkout use-fork
$ yarn
$ yarn start
...
/Users/yuya/src/github.com/yuya-takeyama/strict-loader-test/foo.js:7
    throw new Error('Fail');
          ^
Error: Fail
    at bar (/Users/yuya/src/github.com/yuya-takeyama/strict-loader-test/foo.js:7:11)
    at foo (/Users/yuya/src/github.com/yuya-takeyama/strict-loader-test/foo.js:2:3)
    at Object.<anonymous> (/Users/yuya/src/github.com/yuya-takeyama/strict-loader-test/index.js:5:1)
...
error Command failed with exit code 1.

[mistadikay]

@yuya-takeyama thanks for the PR! published as v1.2.0. I don't use this loader anymore, so let me know how it works for you.

[yuya-takeyama]

Thank you @mistadikay, now I upgraded strict-loader and it worked as I expected!