LoongArch: Add relaxation for R_LARCH_CALL36

This relaxation is effective for both macro instructions (call36, tail36)
and explicit relocation instructions (pcaddu18i + jirl).

call36 f	  ->	bl f
  R_LARCH_CALL36  ->	  R_LARCH_B26

tail36 $t0, f	  ->	b f
  R_LARCH_CALL36  ->	  R_LARCH_B26
11 files changed