[Win32] Replace magic GDI+ image arrays

[HeikoKlare]

Summary

• replace the magic long[2] GDI+ image return value with a dedicated Image.GdipImage record
• centralize temporary bitmap and heap buffer cleanup through GdipImage.destroy() in GC and Pattern
• remove the stale Win32 import from Pattern

Why

createGdipImageFromHandle() always returns the same two-part result: the temporary GDI+ bitmap and an optional heap-backed pixel buffer that must be freed together. Representing that value as long[2] leaves the meaning of gdipImage[0] and gdipImage[1] implicit and pushes cleanup knowledge into each caller.

This change gives that result explicit semantics via Image.GdipImage, moves ownership cleanup to GdipImage.destroy(), and updates Pattern.cleanupBitmap() to track whether a temporary image is present directly instead of inferring state from the returned array length.

Notes

• Pattern.cleanupBitmap() now tracks ownership explicitly instead of relying on the returned array length
• This draft PR was created with Copilot.

[github-actions]

Test Results (win32)

   30 files  ±0     30 suites  ±0   4m 40s ⏱️ +12s
4 677 tests ±0  4 604 ✅ ±0  73 💤 ±0  0 ❌ ±0 
1 211 runs  ±0  1 187 ✅ ±0  24 💤 ±0  0 ❌ ±0 

Results for commit f6074a7. ± Comparison against base commit 75a088f.

♻️ This comment has been updated with latest results.

[Copilot]

Pull request overview

This PR replaces the implicit long[2] GDI+ image/pixels tuple with an explicit Image.GdipImage record, centralizing GDI+ bitmap + heap pixel-buffer cleanup via GdipImage.destroy() and updating Win32 drawing/brush code to use it.

Changes:

• Introduce Image.GdipImage(bitmap, pixels) and update Image#createGdipImage* to return it instead of long[].
• Update GC#drawImage(...) to use GdipImage with try/finally-based cleanup.
• Update Pattern image-pattern handling to track/destroy the temporary GDI+ image via GdipImage.destroy() and remove an unused Win32 import.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/Pattern.java	Switch image-pattern temporary bitmap tracking/cleanup to Image.GdipImage.destroy(); remove unused Win32 import.
bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/Image.java	Add GdipImage record and return it from createGdipImage* to make ownership/cleanup explicit.
bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/GC.java	Use GdipImage in the GDI+ draw path and ensure centralized cleanup in a finally block.

[Copilot]

In cleanupBitmap(), the local variable name image shadows the enclosing Pattern's image field and reads ambiguously (it’s actually the temporary GDI+ image wrapper). Rename the local to something like gdipToDestroy/tempGdipImage to avoid confusion during maintenance.

Suggested change

	Image.GdipImage image = gdipImage;
	gdipImage = null;
	image.destroy();
	Image.GdipImage tempGdipImage = gdipImage;
	gdipImage = null;
	tempGdipImage.destroy();

[HeikoKlare]

Renamed the local to tempGdipImage and updated the branch. This is resolved now.