maint: with split lines, don't leave an operator at end of line

maint: with split lines, don't leave an operator at end of line

* src/copy.c (copy_reg): Split an expression before a binary operator,
not after it.
* src/cut.c (set_fields): Likewise.
* src/id.c (main): Likewise.
* src/install.c (setdefaultfilecon): Likewise.
* src/join.c (ignore_case): Likewise.
* src/pr.c (cols_ready_to_print, init_parameters, print_page): Likewise.
* src/stty.c (set_window_size): Likewise.
* src/wc.c (SUPPORT_OLD_MBRTOWC): Likewise.
* src/who.c (scan_entries): Likewise.
* src/test.c (binary_operator): Join a split line.
* src/extent-scan.c (extent_scan_read): Move an ">" from end of line
to beginning of the following.
Likewise for two other expressions.