RFR: 8331467: ImageReaderFactory can cause a ClassNotFoundException if the default FileSystemProvider is not the system-default provider [v6]

[liyazzi]

> For two cases:
> 
> 1. When the ImageReaderFactory was loaded by local jdk,that means the ImageReaderFactory was loaded by boot class loader,then init the `Path BOOT_MODULES_JIMAGE` by using `sun.nio.fs.DefaultFileSystemProvider` which is obtained through reflection,due to it is in jdk internal.
> 2. When loaded by a target jdk, such as jdk8 runtime, then use the Java 8 compatible APIs: `FileSystems.getDefault()` to init the `BOOT_MODULES_JIMAGE` field.
> Then we can avoid the circular dependencies in class loading caused by loading the defaultSystemProvider.

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

  add test case in test/jdk/java/nio/file/spi/SetDefaultProvider.java as the test of this issue

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22628/files
  - new: https://git.openjdk.org/jdk/pull/22628/files/c29c6f03..e3c336c7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22628&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22628&range=04-05

  Stats: 499 lines in 5 files changed: 200 ins; 297 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/22628.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22628/head:pull/22628

PR: https://git.openjdk.org/jdk/pull/22628