Reland "[llvm-readobj] Simplify usage of -codeview flag"

Relands r255790 with fixed tests.

llvm-svn: 255793
diff --git a/llvm/tools/llvm-readobj/llvm-readobj.cpp b/llvm/tools/llvm-readobj/llvm-readobj.cpp
index 2a75aba..92ee299 100644
--- a/llvm/tools/llvm-readobj/llvm-readobj.cpp
+++ b/llvm/tools/llvm-readobj/llvm-readobj.cpp
@@ -354,6 +354,8 @@
       Dumper->printCOFFDirectives();
     if (opts::COFFBaseRelocs)
       Dumper->printCOFFBaseReloc();
+    if (opts::CodeView)
+      Dumper->printCodeViewDebugInfo();
   }
   if (Obj->isMachO()) {
     if (opts::MachODataInCode)