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

Broked BB again:

TEST 'LLVM :: DebugInfo/X86/dbg-value-regmask-clobber.ll' FAILED
...
LLVM ERROR: Section was outside of section table.

llvm-svn: 303984

llvm/lib/Object/COFFObjectFile.cpp

@@ -293,10 +293,6 @@ uint64_t COFFObjectFile::getSectionAddress(DataRefImpl Ref) const {
   return Result;
 }
 
-uint64_t COFFObjectFile::getSectionIndex(DataRefImpl Sec) const {
-  return toSec(Sec) - SectionTable;
-}
-
 uint64_t COFFObjectFile::getSectionSize(DataRefImpl Ref) const {
   return getSectionSize(toSec(Ref));
 }