Fixed ObjectFile functions:

Fixed ObjectFile functions:
- getSymbolOffset() renamed as getSymbolFileOffset()
- getSymbolFileOffset(), getSymbolAddress(), getRelocationAddress() returns same result for ELFObjectFile, MachOObjectFile and COFFObjectFile.
- added getRelocationOffset()
- fixed MachOObjectFile::getSymbolSize()
- fixed MachOObjectFile::getSymbolSection()
- fixed MachOObjectFile::getSymbolOffset() for symbols without section data.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145408 91177308-0d34-0410-b5e6-96231b3b80d8