RFR: 8077587: BigInteger Roots [v20]

[fabioromano1]

> This PR implements nth root computation for BigIntegers using Newton method.

fabioromano1 has updated the pull request incrementally with one additional commit since the last revision:

  Avoid to discard fraction bits in the initial estimate

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24898/files
  - new: https://git.openjdk.org/jdk/pull/24898/files/6dcd6792..8fabf141

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24898&range=19
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24898&range=18-19

  Stats: 43 lines in 1 file changed: 30 ins; 3 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/24898.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24898/head:pull/24898

PR: https://git.openjdk.org/jdk/pull/24898