Fix ProguardLexer for Windows
Fix ProguardLexer for Windows

Summary: The path separator is `;` on Windows.

Reviewed By: minjang

Differential Revision: D26835889

fbshipit-source-id: 418a716241c6ab82b457904c3cb071c1f10ef9f1

facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex,facebook/redex