Merging //UE4/Dev-Main to Dev-Geometry (from CL: 3492074)

#rb none

[CL 3493369 by Mike Fricker in Dev-Geometry branch]

Engine/Source/Developer/CrashDebugHelper/Private/CrashDebugHelperModule.cpp

@@ -17,6 +17,9 @@ DEFINE_LOG_CATEGORY(LogCrashDebugHelper);
 #elif PLATFORM_MAC
 	#include "CrashDebugHelperMac.h"
 
+#elif PLATFORM_IOS
+	#include "CrashDebugHelperIOS.h"
+
 #else
 	#error "Unknown platform"
 #endif