X87: Change num_double_registers() to num_allocatable_double_registers() for TestStackSlot.

test/cctest/compiler/test-run-native-calls.cc

Index: test/cctest/compiler/test-run-native-calls.cc
diff --git a/test/cctest/compiler/test-run-native-calls.cc b/test/cctest/compiler/test-run-native-calls.cc
index a1808d2bd6c2d529097f5a09bcda300f76c06aa0..89114097d814db0f28f71f7c18cd4577110ab60a 100644
--- a/test/cctest/compiler/test-run-native-calls.cc
+++ b/test/cctest/compiler/test-run-native-calls.cc
@@ -1163,7 +1163,7 @@ void TestStackSlot(MachineType slot_type, T expected) {
   // function g from f which writes into the stack slot of f.
 
   if (RegisterConfiguration::ArchDefault(RegisterConfiguration::TURBOFAN)
-          ->num_double_registers() < 2)
+          ->num_allocatable_double_registers() < 2)
     return;
 
   Isolate* isolate = CcTest::InitIsolateOnce();