[RISCV] Add test case for Zfa fli.s miscompile. NFC

The f32 matching code for fli was hacked to allow the f16 minimum value
to match for the fli.h instruction in the assembler. This was done
because the assembler parses the floating point literal for fli.h,
fli.s, and fli.d as a single precision value.

Unfortunately, this function is also used by CodeGen and causes
this value to be miscompiled for f32.