https://gcc.gnu.org/legacy-ml/gcc-patches/2014-04/msg00498.html
Jason Merrill - Re: [PATCH] Fix ICE with -flto -fno-use-linker-plugin (PR lto/60567)
https://www.intel.com/content/www/us/en/docs/dpcpp-cpp-compiler/developer-guide-reference/2025-1/flto.html
flto
Enables whole program link time optimization (LTO).