Revert r303978 "[DWARF] - Make collectAddressRanges() return section index in addition to Low/High PC"

It failed BB.

llvm-svn: 303981

llvm/lib/Object/MachOObjectFile.cpp

@@ -1820,10 +1820,6 @@ uint64_t MachOObjectFile::getSectionAddress(DataRefImpl Sec) const {
   return getSection(Sec).addr;
 }
 
-uint64_t MachOObjectFile::getSectionIndex(DataRefImpl Sec) const {
-  return Sec.d.a;
-}
-
 uint64_t MachOObjectFile::getSectionSize(DataRefImpl Sec) const {
   // In the case if a malformed Mach-O file where the section offset is past
   // the end of the file or some part of the section size is past the end of