RFR: 8356891: Some code simplifications for basic BigIntegers' bit operations [v9]

[fabioromano1]

> Some changes in `Biginteger`s' bit operations that increase the code readability and slightly optimize the execution time.

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

  Removed numberOfTrailingZeros() as a duplicate of the cached getLowestSetBit()

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/25166/files
  - new: https://git.openjdk.org/jdk/pull/25166/files/b151b7e3..b74fefa5

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25166&range=08
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25166&range=07-08

  Stats: 18 lines in 1 file changed: 5 ins; 11 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/25166.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25166/head:pull/25166

PR: https://git.openjdk.org/jdk/pull/25166