Move platform abstraction to base library

test/cctest/test-code-stubs-arm64.cc

Index: test/cctest/test-code-stubs-arm64.cc
diff --git a/test/cctest/test-code-stubs-arm64.cc b/test/cctest/test-code-stubs-arm64.cc
index be97637c4eb30380b0b928748ab72bad18f9b145..6d5b0f49be786a3d50003f01dc5ad00fb74b897a 100644
--- a/test/cctest/test-code-stubs-arm64.cc
+++ b/test/cctest/test-code-stubs-arm64.cc
@@ -29,10 +29,10 @@
 
 #include "src/v8.h"
 
+#include "src/base/platform/platform.h"
 #include "src/code-stubs.h"
 #include "src/factory.h"
 #include "src/macro-assembler.h"
-#include "src/platform.h"
 #include "src/simulator.h"
 #include "test/cctest/cctest.h"
 #include "test/cctest/test-code-stubs.h"
@@ -47,9 +47,8 @@ ConvertDToIFunc MakeConvertDToIFuncTrampoline(Isolate* isolate,
                                               bool inline_fastpath) {
   // Allocate an executable page of memory.
   size_t actual_size = 4 * Assembler::kMinimalBufferSize;
-  byte* buffer = static_cast<byte*>(OS::Allocate(actual_size,
-                                                 &actual_size,
-                                                 true));
+  byte* buffer = static_cast<byte*>(
+      v8::base::OS::Allocate(actual_size, &actual_size, true));
   CHECK(buffer);
   HandleScope handles(isolate);
   MacroAssembler masm(isolate, buffer, static_cast<int>(actual_size));
@@ -123,7 +122,7 @@ ConvertDToIFunc MakeConvertDToIFuncTrampoline(Isolate* isolate,
 
   CodeDesc desc;
   masm.GetCode(&desc);
-  CPU::FlushICache(buffer, actual_size);
+  CpuFeatures::FlushICache(buffer, actual_size);
   return (reinterpret_cast<ConvertDToIFunc>(
       reinterpret_cast<intptr_t>(buffer)));
 }