Delete UnknownAddress. It is a perfectly valid symbol value.

getSymbolValue now returns a value that in convenient for most callers:
* 0 for undefined
* symbol size for common symbols
* offset/address for symbols the rest

Code that needs something more specific can check getSymbolFlags.

llvm-svn: 241605
diff --git a/llvm/lib/Object/COFFObjectFile.cpp b/llvm/lib/Object/COFFObjectFile.cpp
index 5f9b4fa..bcca983 100644
--- a/llvm/lib/Object/COFFObjectFile.cpp
+++ b/llvm/lib/Object/COFFObjectFile.cpp
@@ -154,13 +154,8 @@
   return Result;
 }
 
-uint64_t COFFObjectFile::getSymbolValue(DataRefImpl Ref) const {
-  COFFSymbolRef Sym = getCOFFSymbol(Ref);
-
-  if (Sym.isAnyUndefined() || Sym.isCommon())
-    return UnknownAddress;
-
-  return Sym.getValue();
+uint64_t COFFObjectFile::getSymbolValueImpl(DataRefImpl Ref) const {
+  return getCOFFSymbol(Ref).getValue();
 }
 
 ErrorOr<uint64_t> COFFObjectFile::getSymbolAddress(DataRefImpl Ref) const {