[AMDGPU][COMGR] Add hotswap text displacement infrastructure

[harsh-amd]

Summary

• Add COMGR hotswap text-displacement infrastructure for cases where a patch grows .text directly instead of using only appended trampolines.
• Update hotswap patch emission to use displacement edits when the replacement needs to grow instruction bytes in place.
• Add displacement planning, section/symbol adjustment, branch re-encoding, relocation rejection, and kernel-descriptor entry update coverage.
• Update existing hotswap lit checks for displacement-aware output.

Stack

1. [AMDGPU][COMGR] Remove COMGR hotswap HSA tool #3007: COMGR hotswap tool removal.
2. AMDGPU: add hotswap entry trampoline core #3008: trampoline implementation.
3. This PR: displacement infrastructure.

GitHub cannot use fork-only branches as ROCm PR bases, so this PR still targets amd-staging. The layer-only diff is harsh-amd:comgr-hotswap-entry-trampolines...harsh-amd:hotswap-entry-trampolines.

Testing

• git diff --check comgr-hotswap-entry-trampolines..comgr-hotswap-displacement
• make -j$(nproc) HotswapElfTests HotswapMCTests hotswap-rewrite in build-comgr-displacement-shared
• build-comgr-displacement-shared/test-unit/HotswapElfTests
• build-comgr-displacement-shared/test-unit/HotswapMCTests
• make -j$(nproc) test-lit in build-comgr-displacement-shared (70 passed / 11 unsupported)