fix: support nested filenames in bundle for different OS

[ideffix]

trafficstars

In my project bundle sometimes contained nested path like somePath\index.css but normalizePath function is changing all back slashes to forward slashes. So if my bundle contains field somePath\index.css and normalizePath returned somePath/index.css I ended up with error: [!] (plugin postcss) TypeError: Cannot read property 'modules' of undefined This PR is fixing it by additionally checking bundle for non-normalizePath.

[codecov[bot]]

Codecov Report

Merging #393 (633dae1) into master (118253e) will increase coverage by 0.04%. The diff coverage is 100.00%.

:exclamation: Current head 633dae1 differs from pull request most recent head 23ad6ea. Consider uploading reports for the commit 23ad6ea to get more accurate results

@@            Coverage Diff             @@
##           master     #393      +/-   ##
==========================================
+ Coverage   92.94%   92.98%   +0.04%     
==========================================
  Files          10       10              
  Lines         326      328       +2     
  Branches      115      117       +2     
==========================================
+ Hits          303      305       +2     
  Misses         22       22              
  Partials        1        1              

Impacted Files	Coverage Δ
src/index.js	100.00% <100.00%> (ø)

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[ideffix]

@egoist any chance of having it merged?