Prefer symbols from .o over .so.

This matches the behavior of gold and bfd ld.

llvm-svn: 258102
diff --git a/lld/ELF/Symbols.cpp b/lld/ELF/Symbols.cpp
index aa7c5d1..dc04370 100644
--- a/lld/ELF/Symbols.cpp
+++ b/lld/ELF/Symbols.cpp
@@ -39,8 +39,9 @@
 template <class ELFT> int SymbolBody::compare(SymbolBody *Other) {
   typedef typename ELFFile<ELFT>::uintX_t uintX_t;
   assert(!isLazy() && !Other->isLazy());
-  std::pair<bool, bool> L(isDefined(), !isWeak());
-  std::pair<bool, bool> R(Other->isDefined(), !Other->isWeak());
+  std::tuple<bool, bool, bool> L(isDefined(), !isShared(), !isWeak());
+  std::tuple<bool, bool, bool> R(Other->isDefined(), !Other->isShared(),
+                                 !Other->isWeak());
 
   // Normalize
   if (L > R)
@@ -54,11 +55,7 @@
 
   if (L != R)
     return -1;
-  if (!L.first || !L.second)
-    return 1;
-  if (isShared())
-    return -1;
-  if (Other->isShared())
+  if (!std::get<0>(L) || !std::get<1>(L) || !std::get<2>(L))
     return 1;
   if (isCommon()) {
     if (!Other->isCommon())