[ARM] Use std::swap instead of manually swapping
* config/arm/arm.md (unaligned_loaddi): Use std::swap instead of
manual swapping implementation.
(movcond_addsi): Likewise.
* config/arm/arm.c (arm_canonicalize_comparison): Likewise.
(arm_select_dominance_cc_mode): Likewise.
(arm_reload_out_hi): Likewise.
(gen_operands_ldrd_strd): Likewise.
(output_move_double): Likewise.
(arm_print_operand_address): Likewise.
(thumb_output_move_mem_multiple): Likewise.
(SWAP_RTX): Delete.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@217701 138bc75d-0d04-0410-961f-82ee72b054a4