[torch.compile] Improve cold and warm start compile tests (#35709)

Signed-off-by: Richard Zou <zou3519@gmail.com>

vllm/compilation/compiler_interface.py

@@ -368,6 +368,7 @@ class InductorStandaloneAdaptor(CompilerInterface):
         inductor_compiled_graph = torch._inductor.CompiledArtifact.load(
             path=path, format=self.save_format
         )
+        compilation_counter.num_compiled_artifacts_loaded += 1
         from torch._inductor.compile_fx import graph_returns_tuple
 
         returns_tuple = graph_returns_tuple(graph)