[Bug target/97324] -mcpu=<value> isn't validated on x86

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97324

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
There is no consistency.
Targets that have all of -march=, -mcpu= and -mtune=:
aarch64, arm, cris, i386 (-mcpu= deprecated and treated as -mtune=), m68k
Targets that have just -march= and -mtune=:
gcn, mips, riscv, s390
Targets that have just -march= and -mcpu=:
csky, iq2000, nds32
Targets that have just -mcpu= and -mtune=:
alpha, arc, rs6000, sparc, visium
Targets that have just -mcpu=:
bfin, frv, m32c, microblaze, msp430, rl78, rx, tilegx, tilepro
Targets that have just -mtune=:
ia64, mn10300
Targets that have just -march=:
c6x, nios2, pa