Support for single-underscore Microsoft keywords

I'm using ReSharper with a large legacy C/C++ project. This project happens to use single-underscore versions of ANSI keywords such as _int64 and _int32. ReSharper doesn't recognize these types, so I have thousands of red squiggles. 

For example, on a line such as:

    unsigned _int64 x;

When I hover over the resulting red squiggle I see:

    "(Local variable) unsigned _int64"

    "Local variable '_int64' is never used"

    "Expected ';'"

Microsoft supports both the single and double underscore versions of the keywords according to this article: https://msdn.microsoft.com/en-us/library/2e6a4at9.aspx.

Is there any way to enable support for the single-underscores in ReSharper C++?