A brief survey of priority_queue usage in the tree turned this up

as a questionable case, but the code isn't actually needed.

llvm-svn: 52657

llvm/lib/CodeGen/RegAllocLinearScan.cpp

@@ -305,7 +305,7 @@ bool RALinScan::runOnMachineFunction(MachineFunction &fn) {
   spiller_->runOnMachineFunction(*mf_, *vrm_);
   vrm_.reset();  // Free the VirtRegMap
 
-  while (!unhandled_.empty()) unhandled_.pop();
+  assert(unhandled_.empty() && "Unhandled live intervals remain!");
   fixed_.clear();
   active_.clear();
   inactive_.clear();