[RuntimeDyld] Skip undefined symbols when building the symbol table.

Storing these in the symbol table (with zero values) is just wasted space.

llvm-svn: 288225

llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp

@@ -205,6 +205,10 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
        ++I) {
     uint32_t Flags = I->getFlags();
 
+    // Skip undefined symbols.
+    if (Flags & SymbolRef::SF_Undefined)
+      continue;
+
     if (Flags & SymbolRef::SF_Common)
       CommonSymbols.push_back(*I);
     else {