The description is clearly what effect the knob has when set, so the
additional text was unnecessary.
Reviewed by: jhb, se
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29583
LLVM_TARGET_* will auto be set based on LLVM_TARGET_ALL and MK_CLANG.
If LLVM_TARGET_ALL is disabled, during a cross-build, then SYSTEM_COMPILER
and SYSTEM_LINKER are auto disabled.
This option should be used by users rather than the per-arch LLVM_TARGET
options as it is simpler to maintain for them should the supported
target list change.
MFC after: 2 weeks
Reviewed by: sbruno, dim
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D16020
