Fix column alignment in "maint info line-table"

Fix column alignment in "maint info line-table"

Andrew Burgess pointed out on irc that "maint info line-table" doesn't
properly align the table headers.  This patch fixes the problem by
switching the table to use ui-out.

This required a small tweak to one test case, as ui-out will pad a
field using spaces, even at the end of a line.

gdb/ChangeLog
2020-03-20  Tom Tromey  <tromey@adacore.com>

	* symmisc.c (maintenance_print_one_line_table): Use ui_out.

gdb/testsuite/ChangeLog
2020-03-20  Tom Tromey  <tromey@adacore.com>

	* gdb.dwarf2/dw2-ranges-base.exp: Update regular expressions.