Avoids a bleed out attack in which a node can be made to allocate
memory slowly or very fast in small strides, by sending bad data
to code that invokes NewAnyWithCustomTypeURL, in which we
unconditionally returned a new Any object. On a 64-bit machine,
this would waste 96 bytes per invocation even on error.
Added a test to ensure zero allocations with a fixed error returned.
Also added a benchmark which shows reduction in wasted allocations and
wasted CPU time:
```shell
$ benchstat before.txt after.txt
name old time/op new time/op delta
NewAnyWithCustomTypeURLWithErrorReturned-8 142ns ± 6% 55ns ±12% -61.65% (p=0.000 n=9+10)
name old alloc/op new alloc/op delta
NewAnyWithCustomTypeURLWithErrorReturned-8 96.0B ± 0% 0.0B -100.00% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
NewAnyWithCustomTypeURLWithErrorReturned-8 1.00 ± 0% 0.00 -100.00% (p=0.000 n=10+10)
```
Fixes#8537
Emmanuel T Odeke
56fc3fc572