RFR: 8356709: Avoid redundant String formatting in BigDecimal.valueOf(double) [v3]

[Johannes Graham]

> Optimize `BigDecimal.valueOf(double)` by using `FormattedFPDecimal` instead of converting to decimal string and then parsing it. This results in an approximate 6x improvement for me.

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

  address review suggestions

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Changes:
  - all: https://git.openjdk.org/jdk/pull/25173/files
  - new: https://git.openjdk.org/jdk/pull/25173/files/ba8d3933..e7d2d14b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25173&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25173&range=01-02

  Stats: 26 lines in 3 files changed: 2 ins; 12 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/25173.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25173/head:pull/25173

PR: https://git.openjdk.org/jdk/pull/25173