|Enable link-time optimisations in the RawSpeed library
|Add support for Link-Time Optimization with LLVM
|Build using Link Time Optimizations (LTO). Note that GCC is always built with support for building other programs with LTO. This USE flag is for whether GCC itself is built and optimized with LTO.
|Build with Link Time Optimizations (via clang's ThinLTO)
|Enable Link Time Optimization (LTO). Requires Gold linker