Revert "[codeview] Make obj2yaml/yaml2obj support .debug$S..."

This is causing failures on linux bots with an invalid stream
read.  It doesn't repro in any configuration on Windows, so
reverting until I have a chance to investigate on Linux.

llvm-svn: 305371
diff --git a/llvm/lib/ObjectYAML/COFFYAML.cpp b/llvm/lib/ObjectYAML/COFFYAML.cpp
index c8cbea1..7f9f4c1 100644
--- a/llvm/lib/ObjectYAML/COFFYAML.cpp
+++ b/llvm/lib/ObjectYAML/COFFYAML.cpp
@@ -488,16 +488,7 @@
   IO.mapOptional("VirtualAddress", Sec.Header.VirtualAddress, 0U);
   IO.mapOptional("VirtualSize", Sec.Header.VirtualSize, 0U);
   IO.mapOptional("Alignment", Sec.Alignment, 0U);
-
-  // If this is a .debug$S or .debug$T section parse the semantic representation
-  // of the symbols/types.  If it is any other kind of section, just deal in raw
-  // bytes.
-  IO.mapOptional("SectionData", Sec.SectionData);
-  if (Sec.Name == ".debug$S")
-    IO.mapOptional("Subsections", Sec.DebugS);
-  else if (Sec.Name == ".debug$T")
-    IO.mapOptional("Types", Sec.DebugT);
-
+  IO.mapRequired("SectionData", Sec.SectionData);
   IO.mapOptional("Relocations", Sec.Relocations);
 }