Make FlushICache part of Assembler(Base) and take Isolate as parameter.

test/cctest/test-code-stubs-arm.cc

Index: test/cctest/test-code-stubs-arm.cc
diff --git a/test/cctest/test-code-stubs-arm.cc b/test/cctest/test-code-stubs-arm.cc
index 80403440da55b1ff293a62f9c939fc1ae2688f09..0a2f3691403cc513f738f501557de3a25f8c1f2e 100644
--- a/test/cctest/test-code-stubs-arm.cc
+++ b/test/cctest/test-code-stubs-arm.cc
@@ -126,7 +126,7 @@ ConvertDToIFunc MakeConvertDToIFuncTrampoline(Isolate* isolate,
 
   CodeDesc desc;
   masm.GetCode(&desc);
-  CpuFeatures::FlushICache(buffer, actual_size);
+  Assembler::FlushICacheWithoutIsolate(buffer, actual_size);
   return (reinterpret_cast<ConvertDToIFunc>(
       reinterpret_cast<intptr_t>(buffer)));
 }