Unity 5.3.1p2 IL2CPP fixing #752153 broke my code

I'm using native plugins that use [In, Out] on an array of floats. Everything has been working fine for months, until 5.3.1p2. Now, my code is breaking when I try to PInvoke the following function:

at runtime, I land here:

Unity 5.3.1p2 IL2CPP fixing #752153 broke my code