Remove now dead code.

After LLVM r222434, the Variables field of DISubprograms for forward
declarations will always be null. No need to keep code around to
delete them.

llvm-svn: 222437

clang/lib/CodeGen/CGDebugInfo.cpp

@@ -3413,13 +3413,6 @@ void CGDebugInfo::finalize() {
     else
       VH = it->second;
 
-    // Functions have a fake temporary MDNode operand that is supposed
-    // to get RAUWed upon DIBuilder finalization. Do not leak these
-    // nodes for the temporary functions we are about to delete.
-    if (FwdDecl.isSubprogram())
-      if (llvm::MDNode *Vars = llvm::DISubprogram(FwdDecl).getVariablesNodes())
-        llvm::MDNode::deleteTemporary(Vars);
-
     FwdDecl.replaceAllUsesWith(CGM.getLLVMContext(),
                                llvm::DIDescriptor(cast<llvm::MDNode>(VH)));
   }