Fix buffer overrun in proguard map parsing
Fix buffer overrun in proguard map parsing

Summary:Yep, I found a >4k method signature.  Let's just parse this ourselves,
it's actually easier than using sscanf.

Reviewed By: dariorussi

Differential Revision: D3130203

fb-gh-sync-id: 3513e6e2136d12f35944b16c97356b86714a3f2f
fbshipit-source-id: 3513e6e2136d12f35944b16c97356b86714a3f2f

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