Fix crash if PATH contains invalid characters
Fix crash if PATH contains invalid characters

Summary:
Make ExecutableFinder::getPaths() prone to errors

PATH environment variable can contain invalid path components, which should be ignored.
Add ExecutableFinder::getPathSafe() that converts string to path or returns null if it could not be converted

Reviewed By: ilya-klyuchnikov

fbshipit-source-id: 2cb314bbba

Addepar/buck,SeleniumHQ/buck,rmaz/buck,nguyentruongtho/buck,romanoid/buck,brettwooldridge/buck,facebook/buck,JoelMarcey/buck,nguyentruongtho/buck,romanoid/buck,Addepar/buck,kageiit/buck,rmaz/buck,brettwooldridge/buck,romanoid/buck,rmaz/buck,rmaz/buck,nguyentruongtho/buck,romanoid/buck,zpao/buck,JoelMarcey/buck,Addepar/buck,brettwooldridge/buck,kageiit/buck,zpao/buck,brettwooldridge/buck,JoelMarcey/buck,nguyentruongtho/buck,SeleniumHQ/buck,romanoid/buck,SeleniumHQ/buck,SeleniumHQ/buck,facebook/buck,SeleniumHQ/buck,kageiit/buck,brettwooldridge/buck,SeleniumHQ/buck,rmaz/buck,rmaz/buck,rmaz/buck,facebook/buck,romanoid/buck,facebook/buck,brettwooldridge/buck,zpao/buck,SeleniumHQ/buck,facebook/buck,facebook/buck,rmaz/buck,kageiit/buck,brettwooldridge/buck,nguyentruongtho/buck,brettwooldridge/buck,brettwooldridge/buck,JoelMarcey/buck,nguyentruongtho/buck,romanoid/buck,JoelMarcey/buck,Addepar/buck,rmaz/buck,rmaz/buck,facebook/buck,romanoid/buck,Addepar/buck,Addepar/buck,kageiit/buck,SeleniumHQ/buck,Addepar/buck,kageiit/buck,brettwooldridge/buck,nguyentruongtho/buck,romanoid/buck,rmaz/buck,Addepar/buck,rmaz/buck,romanoid/buck,JoelMarcey/buck,rmaz/buck,zpao/buck,SeleniumHQ/buck,JoelMarcey/buck,Addepar/buck,zpao/buck,romanoid/buck,Addepar/buck,kageiit/buck,brettwooldridge/buck,JoelMarcey/buck,Addepar/buck,JoelMarcey/buck,brettwooldridge/buck,JoelMarcey/buck,zpao/buck,SeleniumHQ/buck,JoelMarcey/buck,brettwooldridge/buck,SeleniumHQ/buck,Addepar/buck,JoelMarcey/buck,romanoid/buck,SeleniumHQ/buck,zpao/buck,romanoid/buck,SeleniumHQ/buck,JoelMarcey/buck,Addepar/buck