re PR fortran/38507 (Bogus Warning: Deleted feature: GOTO jumps to END of construct)

fortran/
PR fortran/38507
* gfortran.h (gfc_st_label): Fix comment.
(gfc_exec_op): Add statement code EXEC_END_BLOCK for end of block.
* parse.c (accept_statement): Use EXEC_END_BLOCK for END IF and
END SELECT with labels.
(check_do_closure): Fix formatting.
(parse_do_block): Fix typo in error message.
* resolve.c (code_stack): Remove tail member.  Update comment to
new use of reachable_labels.
(reachable_labels): Rename to ...
(find_reachable_labels): ... this.  Overhaul.  Update preceding
comment.
(resolve_branch): Fix comment preceding function.  Rewrite.
(resolve_code): Update call to find_reachable_labels.  Add code to
deal with EXEC_END_BLOCK.
* st.c (gfc_free_statement): Add code to deal with EXEC_END_BLOCK.
* trans.c (gfc_trans_code): Likewise.
testsuite/
* do_4.f: New.
* goto_2.f90: Correct expected warnings.
* goto_4.f90: Likewise.
* goto_5.f90: New.

From-SVN: r145245