Remove the dependency of Zone on Isolate

src/compiler/pipeline.h

Index: src/compiler/pipeline.h
diff --git a/src/compiler/pipeline.h b/src/compiler/pipeline.h
index 59070d4a9e0be43761c494a85002810a5d3810aa..03d889b0b02581f06eab006806706a51a145c66c 100644
--- a/src/compiler/pipeline.h
+++ b/src/compiler/pipeline.h
@@ -37,7 +37,8 @@ class Pipeline {
 
   // Run the pipeline on a machine graph and generate code. If {schedule} is
   // {nullptr}, then compute a new schedule for code generation.
-  static Handle<Code> GenerateCodeForTesting(CallDescriptor* call_descriptor,
+  static Handle<Code> GenerateCodeForTesting(Isolate* isolate,
+                                             CallDescriptor* call_descriptor,
                                              Graph* graph,
                                              Schedule* schedule = nullptr);