[codex] fix MicroBlaze stack protection context layout

[Old-Ding]

Summary

Fixes #1416.

This updates the MicroBlazeV9 assembly context layout so XPAR_MICROBLAZE_USE_STACK_PROTECTION has valid save/restore slots for the stack limit registers:

• adds portSLR_OFFSET and portSHR_OFFSET for 32-bit and __arch64__ layouts
• grows portCONTEXT_SIZE / portMINUS_CONTEXT_SIZE when stack protection is enabled
• keeps existing FPU/no-FPU layouts unchanged when stack protection is disabled

Root cause

portSAVE_CONTEXT and portRESTORE_CONTEXT already save and restore rslr / rshr under XPAR_MICROBLAZE_USE_STACK_PROTECTION, but the offsets were not defined and the task context frame size did not include those fields.

Validation

• Local red check confirmed portSLR_OFFSET / portSHR_OFFSET were missing before the patch.
• Local static layout check passed for the 32-bit and __arch64__ FPU/no-FPU stack-protection combinations.
• git diff --check

I could not run the full MicroBlaze compile locally because mb-gcc is not installed in this Windows environment. The repository GitHub Actions workflow has a dedicated MicroBlazeV9 compile step that should cover this path.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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