[jdk21u-dev] RFR: 8353175: Eliminate double iteration of stream in FieldDescriptor reinitialization

[Radim Vansa]

This backport is a partial fix for a performance regression and prerequisite for backport of https://github.com/openjdk/jdk/pull/24847 (will be done through https://github.com/rvansa/jdk21u-dev/tree/refs/heads/rvansa/backport-8352075)

The backport was not clean; a notable new change is in `reflectionUtils.hpp` (later JDK versions remove the affected class) - I am adding `friend class FieldStream` to `InstanceKlass` to accomodate for this.

Backport-of: f169fc5a99ee2b485e156c043134ab76b7e5ebd9

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Commit messages:
 - Backport f169fc5a99ee2b485e156c043134ab76b7e5ebd9

Changes: https://git.openjdk.org/jdk21u-dev/pull/2010/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=2010&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8353175
  Stats: 33 lines in 7 files changed: 2 ins; 11 del; 20 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/2010.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/2010/head:pull/2010

PR: https://git.openjdk.org/jdk21u-dev/pull/2010