[patch] [python] PR python/15461 (gate architecture calls)

[Tom Tromey]

Phil> I don't disagree on the efficiency argument, but my goal here was to
Phil> follow the pattern that other objects use to determine validity of the
Phil> underlying GDB data. To bring a sense of uniformity to how we do
Phil> things in Python. So how we check a gdb.Frame's, et al, validity, the
Phil> pattern will be the same, as far as possible, for other objects.

Ok.

If you look at other ones, they set the Python exception.  At least that
is true for py-block.c (twice), py-inferior.c, py-inthread.c,
py-symbol.c, py-symtab.c (twice), etc.

FWIW I don't mind inconsistency in these little details.  What matters
is the context in which the macro is most useful.

Tom