[Bug target/111139] RISC-V: improve scalar constants cost model

[vineetg at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111139

--- Comment #2 from Vineet Gupta <vineetg at gcc dot gnu.org> ---
Test case to help drive some of this:

unsigned long long f5(unsigned long long i)
{
  return i * 0x0202020202020202ULL;
}