objdump: Don't print a (always 0) size for MachO symbols.

Only common symbol on MachO and COFF have a size.

For COFF we already had a custom format.

For MachO, there is no native objdump and we were printing it as ELF. Now
we only print the sizes for symbols that actually have them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240422 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed