[Bug lto/64343] [5 Regression] lto compile options

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64343

--- Comment #2 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
This is intended change. Compiling with -O0 -flto and linking with -O3 will not
really give you -O3 optimized code in earlier compilers either; you will not
get any of early optimizations and inlining will not use any of the more
advanced optimizations.

THe purpose of OPTIMIZE/TARGET_OPTION node streaming is to make LTO closer to
non-LTO copmilation by making the compile time flags to matter.  This allows
you to i.e. combine -ffast-math/-fno-fast-math units well or build part of
program with different target options.