python/19506 -- gdb.Breakpoint address location regression

python/19506 -- gdb.Breakpoint address location regression

Now that "legacy" linespecs benefit from consolidated support in
string_to_event_location_basic, python's Breakpoint command should use this
function to turn strings into event locations.

As a result, this patch fixes python/19506. Before:

(gdb) python gdb.Breakpoint("*main")
Traceback (most recent call last):
  File "<string>", line 1, in <module>
RuntimeError: Function "*main" not defined.
Error while executing Python code.

After:

(gdb) python gdb.Breakpoint("*main")
Breakpoint 1 at 0x4005fb: file ../../../src/gdb/testsuite/gdb.python/py-breakpoint.c, line 32.

gdb/ChangeLog

	PR python/19506
	* python/py-breakpoint.c (bppy_init): Use
	string_to_event_location_basic instead of new_linespec_location.

gdb/testsuite/ChangeLog

	PR python/19506
	* gdb.python/py-breakpoint.exp (test_bkpt_address): New procedure.
	(toplevel): Call test_bkpt_address.