Simple VXL update

[dzenanz]

Update vendored VNL/vxl to vxl master cf2b6e0f via Modules/ThirdParty/VNL/UpdateFromUpstream.sh. Rebased onto current main; single snapshot + subtree merge, no hand-applied cherry-picks.

This snapshot natively includes four vxl fixes that were merged upstream today (vxl/vxl#1047, #1048, #1049, #1050), so the earlier interim cherry-pick commits are gone — the imported tree carries them directly.

I think it is advantageous to merge this before #6421, so only the differences related to pruning appear there.

What changed since the previous draft

The previous revision was VXL 2026-06-02 (30cfa520) plus four manual (cherry-pick vxl/vxl#…) commits applied on top of a stale main. Those cherry-picks have all landed in vxl upstream, so this revision re-runs UpdateFromUpstream.sh against vxl master cf2b6e0f (which contains them) and drops the cherry-picks entirely.

The resulting vendored Modules/ThirdParty/VNL/src/vxl tree is byte-identical to the previous draft's tree — only the commit topology changed (clean VXL 2026-06-08 (cf2b6e0f) snapshot + -Xsubtree merge, rebased onto current main).

vxl PR	Fix
#1047	Export vxl_platform_math even when VXL_NO_EXPORT is ON
#1048	VALID_CXX_STANDARDS = 17/20/23 (drop 11/14)
#1049	Drop redundant static_cast<int> in vnl_rnpoly_solve powr()
#1050	Validate size_t→int before narrowing in vnl_powell_1dfun ctor

PR Checklist

• No API changes were made (or the changes have been approved)
• No major design changes were made (or the changes have been approved)

[dzenanz]

Given the amount of failures, maybe this intermediate step is not advantageous? Leaving it up to you Hans.

[hjmjohnson]

@dzenanz Thanks for the suggestion. I think this is a good idea. I will take over this work and syncronize the two back to back updates of VNL. Step 1: Minimal updates against VNL upstream (pushing to VXL/vnl the recommendations where appropriate), then Step 2: Aggressive local changes to the InsightSoftwareConsortium/vxl @ for/itk-vxl-master diet targeted only for what ITK needs

[dzenanz]

Shouldn't we merge the fixes in VXL first, then re-run the update script here?

[hjmjohnson]

@dzenanz
vxl/vxl#1050
#1050 opened 1 hour ago by hjmjohnson Member
1

vxl/vxl#1049
#1049 opened 1 hour ago by hjmjohnson Member
• Draft
1

vxl/vxl#1048
#1048 opened 1 hour ago by hjmjohnson Member
1

vxl/vxl#1047
#1047 opened 1 hour ago by hjmjohnson Member

Either way should produce the same codebase result.

[hjmjohnson]

@dzenanz Will update in a few minutes. I just noticed your approvals on those.