To do this:
1. Deine FeatureRelax to enable/disable linker relaxation
2. Add fixup_riscv_relax fixup types which eventually will transfer to R_RISCV_RELAX relocation type.
3. Insert R_RISCV_RELAX relocation type to auipc function call expression when linker relaxation enabled.
4. Define shouldForceRelocation to preserve relocation types when linker relaxation enabled. So then linker could fixup branches offset while relaxation.