RFR: 8343700: ceil_log2 should not loop endlessly [v8]

[Sonia Zaldana Calles]

> Hi all, 
> 
> This PR addresses [8343700](https://bugs.openjdk.org/browse/JDK-8343700) where ceil_log2 looped endlessly if the input value has the highest bit set. 
> 
> I also dealt with the case where we try to find ceil_log2(1) which would've returned 1 as opposed to 0. 
> 
> Cheers, 
> Sonia

Sonia Zaldana Calles has updated the pull request incrementally with one additional commit since the last revision:

  death test

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/22074/files
  - new: https://git.openjdk.org/jdk/pull/22074/files/9e4c99fd..66407706

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22074&range=07
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22074&range=06-07

  Stats: 8 lines in 1 file changed: 8 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/22074.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22074/head:pull/22074

PR: https://git.openjdk.org/jdk/pull/22074