How to set up clang++ in Oracle Solaris 11.4 Beta?

I'm trying Oracle Solaris 11.4 Beta.

My baseline is the standard text installation pointing to a local repo.

I have successfully installed the newer GNU packages:

# pkg install --be-name developer-gnu developer-gnu

But it seems I couldn't get clang working by the simple addition of:

# pkg install --be-name clang clang

When I attempt a simple test I get the following:

user1@s11.4b:/tmp

$ clang++ -v -std=c++11 -m64 -o test test.cpp

UseGnuAs: true

UseGnuLd: false

UseGoldLd: false

UseSunLd: true

UseMediatedGCCToolChainPath: false

UseSpecifiedGCCToolChainPath: false

GCCInstallDir: /usr/gcc/

GCCMajor: 5

GCCMajorMinorMicro:

GCCInternalLibDir: /usr/gcc/5/lib/gcc/x86_64-pc-solaris2.11/

GCCInternalMultiLibDir: /usr/gcc/5/lib/gcc/x86_64-pc-solaris2.11//32