[Interpreter] Allocate registers used as call arguments on-demand.

test/unittests/interpreter/bytecode-register-allocator-unittest.cc

Index: test/unittests/interpreter/bytecode-register-allocator-unittest.cc
diff --git a/test/unittests/interpreter/bytecode-register-allocator-unittest.cc b/test/unittests/interpreter/bytecode-register-allocator-unittest.cc
index f06e454cc943b233fffdfd95e31c61a9ea7f1320..81c6da5f8fe9da9e12ce029599f512b3b8c08631 100644
--- a/test/unittests/interpreter/bytecode-register-allocator-unittest.cc
+++ b/test/unittests/interpreter/bytecode-register-allocator-unittest.cc
@@ -91,6 +91,23 @@ TEST_F(BytecodeRegisterAllocatorTest, RegisterListAllocations) {
   CHECK_EQ(allocator()->next_register_index(), 3);
 }
 
+TEST_F(BytecodeRegisterAllocatorTest, GrowableRegisterListAllocations) {
+  CHECK_EQ(allocator()->maximum_register_count(), 0);
+  Register reg = allocator()->NewRegister();
+  CHECK_EQ(reg.index(), 0);
+  RegisterList reg_list = allocator()->NewGrowableRegisterList();
+  CHECK_EQ(reg_list.register_count(), 0);
+  allocator()->GrowRegisterList(&reg_list);
+  allocator()->GrowRegisterList(&reg_list);
+  allocator()->GrowRegisterList(&reg_list);
+  CHECK_EQ(reg_list.register_count(), 3);
+  CHECK_EQ(reg_list[0].index(), 1);
+  CHECK_EQ(reg_list[1].index(), 2);
+  CHECK_EQ(reg_list[2].index(), 3);
+  CHECK_EQ(allocator()->maximum_register_count(), 4);
+  CHECK_EQ(allocator()->next_register_index(), 4);
+}
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8