* lib/gdb.exp (gdb_test_multiple): Handle "y or [n]", "[y] or n",
and the breakpoint menu. Do not call perror if a prompt is seen.
Consume the following GDB prompt.
* gdb.cp/method2.exp (test_break): Use gdb_test_multiple.
* gdb.cp/namespace.exp: Use gdb_test.
* gdb.cp/templates.exp: Use gdb_test.
(test_template_breakpoints): Use gdb_test_multiple.
* gdb.cp/ovldbreak.exp: Set multiple-symbols to "ask".
Add a couple of tests that verify the behavior when the new setting
is set to "cancel" and "all".
* gdb.cp/method2.exp, gdb.cp/templates.exp: Set multiple-symbols to
"ask" before we start the testing.
