[PR88579, patch] Calculating power of powers of two

[Harald Anlauf]

I was too anxious pressing the send button so that I forgot to mention:

Regtested with no new regressions on x86_64-pc-linux-gnu.

Sorry for that.

Harald

On 01/20/19 23:18, Harald Anlauf wrote:
> Dear all,
> 
> here's my revised patch for the treatment of (2**e) ** n and (- 2**e) **
> n, trying to take into account the bitwidth of the result.
> 
> I've also extended the testcase to sample different integer kinds.
> 
> ChangeLogs see below.
> 
> Note: I don't have commit rights, so please somebody else take care
> of it after review.
> 
> Thanks,
> Harald