MAC: Crash on startup

"MacBook pro 13 2015 with yosemite 10.10.3 just crashed after launching ue4."

The problem is that the recently introduced calls to IsRHIDeviceNVIDIA occur before the Mac code sets the GRHIVendorID value, so the assert fires.

1. Get 4.7.5
2. Run
3. Crash

FOutputDevice::Logf(wchar_t const*, ...) Address = 0x706078f (filename not found) [in UE4Editor-Core.dylib]
FDebug::AssertFailed(char const*, char const*, int, wchar_t const*, ...) Address = 0x703b487 (filename not found) [in UE4Editor-Core.dylib]
IsRHIDeviceNVIDIA() Address = 0xc2bb6f0 (filename not found) [in UE4Editor-RHI.dylib]
FOpenGLBase::ProcessExtensions(FString const&) Address = 0x23b136a7 (filename not found) [in UE4Editor-OpenGLDrv.dylib] FOpenGL3::ProcessExtensions(FString const&) Address = 0x23b1327c (filename not found) [in UE4Editor-OpenGLDrv.dylib] FMacOpenGL::ProcessExtensions(FString const&) Address = 0x23b59a48 (filename not found) [in UE4Editor-OpenGLDrv.dylib] FOpenGLDynamicRHI::FOpenGLDynamicRHI() Address = 0x23b2b90c (filename not found) [in UE4Editor-OpenGLDrv.dylib] FOpenGLDynamicRHIModule::CreateRHI() Address = 0x23b70bce (filename not found) [in UE4Editor-OpenGLDrv.dylib]
RHIInit(bool) Address = 0xc2abff4 (filename not found) [in UE4Editor-RHI.dylib]
FEngineLoop::PreInit(wchar_t const*) Address = 0x6e06f75 (filename not found) [in UE4Editor]
GuardedMain(wchar_t const*) Address = 0x6e13b64 (filename not found) [in UE4Editor]
-[UE4AppDelegate runGameThread:] Address = 0x6e227c3 (filename not found) [in UE4Editor]
-[FCocoaGameThread main] Address = 0x6f70278 (filename not found) [in UE4Editor-Core.dylib]
NSThread__main() Address = 0x940dbdc2 (filename not found) [in Foundation]
_pthread_body() Address = 0x901ff268 (filename not found) [in libsystem_pthread.dylib]
_pthread_body() Address = 0x901ff1e5 (filename not found) [in libsystem_pthread.dylib]
thread_start() Address = 0x901fd41d (filename not found) [in libsystem_pthread.dylib]