Editor now compiles cleanly without warnings, but crashes on startup due to error in intrinsics test. Disabling that runs further, but crashes accessing freed memory. Switching to the ANSI allocator runs further, but crashes in Slate after the splash screen and before the editor window opens. // TODO!
* Switching between Clang/ICL/VS2015/VS2017 is now supported through the same mechanism as switching Visual Studio versions, without requiring any source level changes. To use Clang, set WindowsPlatform.Compiler = WindowsCompiler.Clang from a .target.cs file, or set <WindowsPlatform><Compiler>Clang</Compiler></WindowsPlatform> from BuildConfiguration.xml. To pick a specific toolchain version, set WindowsPlatform.CompilerVersion.
* Clang is now supported through AutoSDKs; will be added to CIS.
* The Samples/Sandbox/Clang project forces Clang to be used from its target.cs file, and allows easily building all editor modules and plugins with Clang on Windows.
* UnrealMathSSE intrinsics have been re-enabled for Clang due to missing functions from the UnrealMathFPU implementation, but causes failure in tests at startup.
* SSE4_CRC32() is disabled in D3D12Pipelinestate.cpp, since intrinsics are only allowed if enabled for the whole target (rather than being used in specific functions due to runtime checks)
#fyi Mike.Fricker, Ben.Woodhouse
#rb none
[CL 4156437 by Ben Marsh in Dev-Core branch]
c56336b9e5