Steps to reproduce:
1. Open the attached project (Unity5_BugReport_APIUpdater_Profiler_1.zip)
2. Execute Mainmenu/BugReport/Profiler
3. Observe a System.MissingMethodException is logged to the Console window

Expected result: The API Updater should update the DLL to the new method signature
Actual result: The API Updater gives an error

Note:
The source code for the DLL can be found in the project as well, it's named ClassLibrary1_Source.zip.

Reproduced with: 5.6.0a1, 5.6.0b2, 5.6.0b3
Not reproduced with: 5.5.0p3
Regression introduced in 5.6.0a1