[llvm-objdump][test] Reorganize ELF --syms tests
Merge symbol-table-elf.test and common-symbol-elf.test, and add some
more tests (invalid st_type, STT_COMMON, STT_GNU_IFUNC, STT_HIOS, STT_LOPROC, SHN_UNDEF, SHN_ABS, SHN_COMMON, STB_GNU_UNIQUE, invalid binding, etc) to test/llvm-objdump/ELF/symbol-table.test
The naming follows test/llvm-{readobj,objcopy}/ELF .
Some discrepancy from GNU objdump:
* STT_COMMON: can be produced with `ld.bfd -r -z common`, but it almost never exists in practice
* STT_GNU_IFUNC: will be fixed by D75793
* STB_GNU_UNIQUE: will be fixed by D75797
* STT_TLS: GNU objdump does not print 'O'
* unknown binding: GNU objdump does not print 'g'. This probably does not matter.
* A reserved symbol index is displayed as *ABS* in GNU objdump. It is not clear what we should print.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D75796