[Comgr][hotswap] Add raise_cli + lit harness for hotswap-raise fixtures

[tgymnich]

Wires up the per-kernel raiser CLI and the lit-harness scaffolding the subsequent handler commits' fixtures consume:

• test-lit/comgr-sources/raise_cli.cpp — minimal --emit-ir driver that calls raiseToIR directly and dumps the resulting Module to stdout via Module::print. Subsequent commits add the default fork mode (kerneldex coverage) and --write-hsaco mode (full pipeline) once hotswap/pipeline.h lands.
• test-lit/CMakeLists.txt — gates a new raise_cli target on COMGR_ENABLE_HOTSWAP_TRANSPILE; links hotswap::transpiler plus comgr-metadata.cpp and the just-extracted comgr-target-init.cpp directly so the binary doesn't pull in the rest of the amd_comgr public surface.
• test-lit/lit.site.cfg.py.in — exposes the COMGR_ENABLE_HOTSWAP_TRANSPILE configure-time value.
• test-lit/lit.cfg.py — adds comgr-hotswap-transpile REQUIRES feature plus the %llvm_mc, %ld_lld, %not, and %raise_cli substitutions every hotswap-raise/ RUN line uses.
• test-unit/CMakeLists.txt — comgr_link_hotswap_transpiler helper grows to compile comgr-target-init.cpp into every unit-test binary so ensureLLVMInitialized resolves at link time.
• src/hotswap/code_object_utils.{h,cpp} — adds the readFile helper raise_cli and (later) the pipeline driver consume to slurp HSACO / IR / asm artefacts off disk; matches the convention of centralising file I/O in the metadata layer.

The raiser stays at its decode-and-bail / IR-scaffold form from the preceding commits. With these in place the lit harness is reachable but every hotswap-raise/ fixture FAILs honestly until the dispatch loop lands at the Wire raiser dispatcher commit.

[tgymnich]

Warning

Stacked PR

1. [Comgr][hotswap] Add bare-bones hotswap transpiler scaffolding #2438
2. [Comgr][hotswap] Add code-object metadata parsing #2437
3. [Comgr][hotswap] Add AMDGPU MC state setup #2439
4. [Comgr][hotswap] Add DecodedInst + basic kernel decoder #2517
5. [Comgr][hotswap] Add wave projection + ISA profile + abi/wave-mask docs #2518
6. [Comgr][hotswap] Add raise_failure + RaiseContext + register file #2551
7. [Comgr][hotswap] Add raise_cli + lit harness for hotswap-raise fixtures #2552 <----
8. [Comgr][hotswap] Add SOPP + SOPC handlers #2553