llvm dev - Feb 2018 - Building llvm-5.0.1 on Solaris 10/sparc

Greetings, All:

I am trying to build llvm-5.0.1 on Solaris 10/Sparc with gcc-5.4.0 as 
follows.

cmake -DLLVM_TARGETS_TO_BUILD="Sparc"
/home/nemo/opt/llvm/llvm-5.0.1-src

I then invoke gmake and the build trundles along and stops as follows.

[ 62%] Building CXX object 
lib/ObjectYAML/CMakeFiles/LLVMObjectYAML.dir/MachOYAML.cpp.o
/home/nemo/opt/llvm/llvm-5.0.1.src/lib/ObjectYAML/MachOYAML.cpp: In 
static member function 'static void llvm::yaml::ScalarTraits<char 
[16]>::output(const char (&)[16], void*, llvm::raw_ostream&)':
/home/nemo/opt/llvm/llvm-5.0.1.src/lib/ObjectYAML/MachOYAML.cpp:40:33: 
error: 'strnlen' was not declared in this scope
    auto Len = strnlen(&Val[0], 16);

gmake[2]: *** 
[lib/ObjectYAML/CMakeFiles/LLVMObjectYAML.dir/MachOYAML.cpp.o] Error 1
gmake[1]: *** [lib/ObjectYAML/CMakeFiles/LLVMObjectYAML.dir/all] Error 2

My main question is: Why are Mach0 tools being built?

Sincerely,
N.