Fixed two register allocator bugs (off-by-one error/failure propagation).

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index f98e6c0306c8ee000cdfa4488e5777d460431def..4a380ef1b1b66b60fd2514f0f50505413215f937 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -725,10 +725,12 @@ LInstruction* LChunkBuilder::AssignPointerMap(LInstruction* instr) {
 LUnallocated* LChunkBuilder::TempRegister() {
   LUnallocated* operand =
       new(zone()) LUnallocated(LUnallocated::MUST_HAVE_REGISTER);
-  operand->set_virtual_register(allocator_->GetVirtualRegister());
+  int vreg = allocator_->GetVirtualRegister();
   if (!allocator_->AllocationOk()) {
-    Abort("Not enough virtual registers (temps).");
+    Abort("Out of virtual registers while trying to allocate temp register.");
+    return NULL;
   }
+  operand->set_virtual_register(vreg);
   return operand;
 }