Revert r270543 ("Recommit r270540")

Failed build bot in another test.
I am sorry for noise.
http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-incremental_check/23679/testReport/junit/LLVM/DebugInfo/llvm_symbolizer_zlib_test/

llvm-svn: 270547

llvm/lib/Object/COFFObjectFile.cpp

@@ -292,10 +292,6 @@ uint64_t COFFObjectFile::getSectionAlignment(DataRefImpl Ref) const {
   return Sec->getAlignment();
 }
 
-bool COFFObjectFile::isSectionCompressed(DataRefImpl Sec) const {
-  return false;
-}
-
 bool COFFObjectFile::isSectionText(DataRefImpl Ref) const {
   const coff_section *Sec = toSec(Ref);
   return Sec->Characteristics & COFF::IMAGE_SCN_CNT_CODE;