Error in parse export for DLL profapi.dll

Describe the bug When a BinHandler is created, the code in charge for parsing the Export table raise an exception. The problematic file is C:\Windows\SysWOW64\profapi.dll (MD5: 2545F5AA189DF907BC4A6E000E231A6D).

To Reproduce Steps to reproduce the behavior:

1. Run code: BinHandler.Init(ISA.OfString "x86", @"C:\Windows\SysWOW64\profapi.dll")
2. See error in PEHelper.getRawOffset, exception message: System.IndexOutOfRangeException: 'Index was outside the bounds of the array.'

Environment (please complete the following information):

• OS: Windows
• B2R2 version: 0.1.1 (2019-03-22)

Additional context The DLL contains a uncommon Export directory table, an example of export is:

Ordinal        Function RVA   Name Ordinal    Name RVA    Name
00000066	00004560	N/A	      N/A	  N/A

This will raise an exception at the following code: let sHdr = headers.SectionHeaders.[idx] where idx has value -1.

[sangkilc]

44d2c8a7c3d92de270a9cfd886c99434b730d931 should fix the issue. Please close the issue if it works for you.

[sangkilc]

Awesome. Will take a look at this ASAP.