[llvm][tools] Extend llvm-objdump to support nested OffloadBinaries (#185425)
Extends llvm-objdump to print the information of images contained in
nested OffloadBinaries. For example, for a binary compiled with #185413
it shows
```
$llvm-objdump --offloading ./a.out
./a.out: file format elf64-x86-64
OFFLOADING IMAGE [0]:
kind elf
arch
triple spirv64-intel
producer openmp
image size 43104 bytes
[Nested OffloadBinary format detected]
Number of inner images: 1
kind spir-v
arch
triple spirv64-intel
producer openmp
image size 42944 bytes
```
New tests are added for clang-ling-wrapper and llvm-offload-binary using
this new functionality.
Depends on #185413
---------
Co-authored-by: Yury Plyakhin <yury.plyakhin@intel.com>