[ELF] - Make SymbolTable::addDefined return Defined.

Now it returns Symbol. This should be NFC that
avoids doing cast at the caller's sides.

Differential revision: https://reviews.llvm.org/D54627

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@347455 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/ELF/SymbolTable.cpp b/ELF/SymbolTable.cpp
index f99b2a3..e372461 100644
--- a/ELF/SymbolTable.cpp
+++ b/ELF/SymbolTable.cpp
@@ -459,9 +459,9 @@
   error(Msg);
 }
 
-Symbol *SymbolTable::addDefined(StringRef Name, uint8_t StOther, uint8_t Type,
-                                uint64_t Value, uint64_t Size, uint8_t Binding,
-                                SectionBase *Section, InputFile *File) {
+Defined *SymbolTable::addDefined(StringRef Name, uint8_t StOther, uint8_t Type,
+                                 uint64_t Value, uint64_t Size, uint8_t Binding,
+                                 SectionBase *Section, InputFile *File) {
   Symbol *S;
   bool WasInserted;
   std::tie(S, WasInserted) = insert(Name, getVisibility(StOther),
@@ -474,7 +474,7 @@
   else if (Cmp == 0)
     reportDuplicate(S, File, dyn_cast_or_null<InputSectionBase>(Section),
                     Value);
-  return S;
+  return cast<Defined>(S);
 }
 
 template <typename ELFT>
diff --git a/ELF/SymbolTable.h b/ELF/SymbolTable.h
index e91e5cc..b5fd8d3 100644
--- a/ELF/SymbolTable.h
+++ b/ELF/SymbolTable.h
@@ -45,9 +45,9 @@
   Symbol *addUndefined(StringRef Name, uint8_t Binding, uint8_t StOther,
                        uint8_t Type, bool CanOmitFromDynSym, InputFile *File);
 
-  Symbol *addDefined(StringRef Name, uint8_t StOther, uint8_t Type,
-                     uint64_t Value, uint64_t Size, uint8_t Binding,
-                     SectionBase *Section, InputFile *File);
+  Defined *addDefined(StringRef Name, uint8_t StOther, uint8_t Type,
+                      uint64_t Value, uint64_t Size, uint8_t Binding,
+                      SectionBase *Section, InputFile *File);
 
   template <class ELFT>
   void addShared(StringRef Name, SharedFile<ELFT> &F,
diff --git a/ELF/Writer.cpp b/ELF/Writer.cpp
index 0eb117a..98a464a 100644
--- a/ELF/Writer.cpp
+++ b/ELF/Writer.cpp
@@ -172,15 +172,14 @@
   Symbol *S = Symtab->find(Name);
   if (!S || S->isDefined())
     return nullptr;
-  Symbol *Sym = Symtab->addDefined(Name, StOther, STT_NOTYPE, Val,
-                                   /*Size=*/0, Binding, Sec,
-                                   /*File=*/nullptr);
-  return cast<Defined>(Sym);
+  return Symtab->addDefined(Name, StOther, STT_NOTYPE, Val,
+                            /*Size=*/0, Binding, Sec,
+                            /*File=*/nullptr);
 }
 
 static Defined *addAbsolute(StringRef Name) {
-  return cast<Defined>(Symtab->addDefined(Name, STV_HIDDEN, STT_NOTYPE, 0, 0,
-                                          STB_GLOBAL, nullptr, nullptr));
+  return Symtab->addDefined(Name, STV_HIDDEN, STT_NOTYPE, 0, 0, STB_GLOBAL,
+                            nullptr, nullptr);
 }
 
 // The linker is expected to define some symbols depending on