remove most uses of Isolate::Current in arch specific files

src/arm/assembler-arm-inl.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 261 matching lines @@
           && ((next_instr & kBlxRegMask) == kBlxRegPattern);
 }
 
 
 bool RelocInfo::IsPatchedDebugBreakSlotSequence() {
   Instr current_instr = Assembler::instr_at(pc_);
   return !Assembler::IsNop(current_instr, Assembler::DEBUG_BREAK_NOP);
 }
 
 
-void RelocInfo::Visit(ObjectVisitor* visitor) {
+void RelocInfo::Visit(Isolate* isolate, ObjectVisitor* visitor) {
   RelocInfo::Mode mode = rmode();
   if (mode == RelocInfo::EMBEDDED_OBJECT) {
     visitor->VisitEmbeddedPointer(this);
   } else if (RelocInfo::IsCodeTarget(mode)) {
     visitor->VisitCodeTarget(this);
   } else if (mode == RelocInfo::CELL) {
     visitor->VisitCell(this);
   } else if (mode == RelocInfo::EXTERNAL_REFERENCE) {
     visitor->VisitExternalReference(this);
   } else if (RelocInfo::IsCodeAgeSequence(mode)) {
     visitor->VisitCodeAgeSequence(this);
 #ifdef ENABLE_DEBUGGER_SUPPORT
-  // TODO(isolates): Get a cached isolate below.
   } else if (((RelocInfo::IsJSReturn(mode) &&
               IsPatchedReturnSequence()) ||
              (RelocInfo::IsDebugBreakSlot(mode) &&
               IsPatchedDebugBreakSlotSequence())) &&
-             Isolate::Current()->debug()->has_break_points()) {
+             isolate->debug()->has_break_points()) {
     visitor->VisitDebugTarget(this);
 #endif
   } else if (RelocInfo::IsRuntimeEntry(mode)) {
     visitor->VisitRuntimeEntry(this);
   }
 }
 
 
 template<typename StaticVisitor>
 void RelocInfo::Visit(Heap* heap) {
@@ skipping 206 matching lines @@
 
 
 void Assembler::set_target_address_at(Address pc, Address target) {
   set_target_pointer_at(pc, target);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_ASSEMBLER_ARM_INL_H_