--symbolize-operands When disassembling, symbolize a branch target operand to print a label instead of a real address.
obj2yaml created test file has many redundant things which are noise, e.g. eh_frame, .note.GNU-stack, STT_FILE. They can all be deleted.
How about using assembly with llvm-mc -filetype=obj? The main thing to test is the code sequence which is opaque as the yaml test (Content). An assembly test is easier to update.
You can order PowerPC before X86 for an alphabetical order.
Don't prefix test names with elf- if they're in an ELF subdirectory.
Similar comment to MaskRay's above - the input probably wants to just be IR or assembly.