[jdk21u-dev] RFR: 8358058: sun/java2d/OpenGL/DrawImageBg.java Test fails intermittently

[Roland Mesde]

Backporting JDK-8358058: sun/java2d/OpenGL/DrawImageBg.java Test fails intermittently.

This PR migrates tests from a closed repository with improvements including corrected thread logic, paint-on-demand behavior, and support for all systems (not just OpenGL).

For parity with Oracle JDK. Already backported to 25.

Ran related tests on linux-x64, linux-aarch64, macos-aarch64 and windows-x64:

make test TEST=test/jdk/sun/java2d/OpenGL/DrawBitmaskImage.java
make test TEST=test/jdk/sun/java2d/OpenGL/DrawBufImgOp.java
make test TEST=test/jdk/sun/java2d/OpenGL/DrawImageBg.java
make test TEST=test/jdk/sun/java2d/OpenGL/LargeOps.java
make test TEST=test/jdk/sun/java2d/OpenGL/OpaqueDest.java
make test TEST=test/jdk/sun/java2d/OpenGL/ScaleParamsOOB.java
make test TEST=test/jdk/sun/java2d/OpenGL/ShapeClip.java
make test TEST=test/jdk/sun/java2d/OpenGL/SrcMaskOps.java
make test TEST=test/jdk/sun/java2d/OpenGL/VolatileSubRegion.java
make test TEST=test/jdk/sun/java2d/OpenGL/XformVolatile.java

Note: test/jdk/sun/java2d/OpenGL/ScaleParamsOOB.java fails on linux-x64 and linux-aarch64 (using libmesa software rendering) with a color mismatch error (expected=ffff0000 actual=ff000000 at x=40 y=40). Issues related to [JDK-8369335](https://bugs.openjdk.org/browse/JDK-8369335) and [JDK-8378113](https://bugs.openjdk.org/browse/JDK-8378113) will be addressed in separate dependent backport PRs.

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Commit messages:
 - Backport ebeb77baaeb6d9098d7462f5ddf61d8583b1e493

Changes: https://git.openjdk.org/jdk21u-dev/pull/2636/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=2636&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8358058
  Stats: 1989 lines in 11 files changed: 1989 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/2636.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/2636/head:pull/2636

PR: https://git.openjdk.org/jdk21u-dev/pull/2636