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

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 9bf72a68d7e42349c821d6883578f0725a6d8c13..50551dba8f20663be82a149bbb59ec6d80757381 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -11120,7 +11120,7 @@ void Code::Relocate(intptr_t delta) {
   for (RelocIterator it(this, RelocInfo::kApplyMask); !it.done(); it.next()) {
     it.rinfo()->apply(delta);
   }
-  CpuFeatures::FlushICache(instruction_start(), instruction_size());
+  Assembler::FlushICache(GetIsolate(), instruction_start(), instruction_size());
 }
 
 
@@ -11174,7 +11174,7 @@ void Code::CopyFrom(const CodeDesc& desc) {
       it.rinfo()->apply(delta);
     }
   }
-  CpuFeatures::FlushICache(instruction_start(), instruction_size());
+  Assembler::FlushICache(GetIsolate(), instruction_start(), instruction_size());
 }