LLVM_DEFAULT_TARGET_TRIPLE was ${TARGET} (redox), so the host clang defaulted
to x86_64-unknown-redox and searched the Redox sysroot for the C++ stdlib when
libclc compiled its host prepare_builtins.cpp -> 'type_traits' file not found.
A host clang must default to the host triple (the redoxer toolchain's clang
does exactly this: Target x86_64-unknown-linux-gnu). Set it to
${COOKBOOK_HOST_TARGET}. libclc's .cl->bitcode compiles pass -target amdgcn
explicitly, so the host default does not affect them.
vasilito
777998a31f