Remove DefinedCommon::Section.

Since CommonInputSection is a singleton class, we don't need
to store pointers to all DefinedCommon symbols.

llvm-svn: 277410
diff --git a/lld/ELF/Symbols.cpp b/lld/ELF/Symbols.cpp
index 6d7e797..b1056f8 100644
--- a/lld/ELF/Symbols.cpp
+++ b/lld/ELF/Symbols.cpp
@@ -63,10 +63,10 @@
       return VA - Out<ELFT>::TlsPhdr->p_vaddr;
     return VA;
   }
-  case SymbolBody::DefinedCommonKind: {
-    auto &D = cast<DefinedCommon<ELFT>>(Body);
-    return D.Section->OutSec->getVA() + D.Section->OutSecOff + D.Offset;
-  }
+  case SymbolBody::DefinedCommonKind:
+    return CommonInputSection<ELFT>::X->OutSec->getVA() +
+           CommonInputSection<ELFT>::X->OutSecOff +
+           cast<DefinedCommon<ELFT>>(Body).Offset;
   case SymbolBody::SharedKind: {
     auto &SS = cast<SharedSymbol<ELFT>>(Body);
     if (!SS.NeedsCopyOrPltAddr)