Merged r13946 into 3.16 branch.

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index e35a381faacd932d223a4a64d1d45a317e491007..967bfa997d2f0231927d203e836c0edd0cf27e6e 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -665,8 +665,12 @@ LInstruction* LChunkBuilder::AssignPointerMap(LInstruction* instr) {
 LUnallocated* LChunkBuilder::TempRegister() {
   LUnallocated* operand =
       new(zone()) LUnallocated(LUnallocated::MUST_HAVE_REGISTER);
-  operand->set_virtual_register(allocator_->GetVirtualRegister());
-  if (!allocator_->AllocationOk()) Abort("Not enough virtual registers.");
+  int vreg = allocator_->GetVirtualRegister();
+  if (!allocator_->AllocationOk()) {
+    Abort("Out of virtual registers while trying to allocate temp register.");
+    return NULL;
+  }
+  operand->set_virtual_register(vreg);
   return operand;
 }