* reload.c (subst_reloads): Take INSN argument.  When
replacing a LABEL_REF in a JUMP_INSN, add a REG_LABEL note.
* reload.h (subst_reloads): Adjust prototype.
* reload1.c (reload_as_needed): Pass INSN to subst_reloads.
* jump.c (mark_all_labels): Canonicalize any REG_LABEL notes
present in JUMP_INSNs and copy them to JUMP_LABEL.
* flow.c (find_label_refs, find_basic_blocks_1): Skip
JUMP_INSNs and insns with REG_LABELs that are followed by
JUMP_INSNs with the same REG_LABEL.
* sched-rgn.c (is_cfg_nonregular): Likewise.
* rtlanal.c (computed_jump_p): Make it false if a REG_LABEL
note is available.
* unroll.c (unroll_loop): Look for REG_LABEL notes in
JUMP_INSNs too.
* rtl.texi (REG_LABEL): Document usage in JUMP_INSNs.

From-SVN: r38755