Revert "Revert "Upgrade to 5.0.71.48"" DO NOT MERGE

This reverts commit f2e3994fa5148cc3d9946666f0b0596290192b0e,
and updates the x64 makefile properly so it doesn't break that
build.

FPIIM-449

Change-Id: Ib83e35bfbae6af627451c926a9650ec57c045605
(cherry picked from commit 109988c7ccb6f3fd1a58574fa3dfb88beaef6632)
diff --git a/src/heap/incremental-marking.h b/src/heap/incremental-marking.h
index be63021..387dd0c 100644
--- a/src/heap/incremental-marking.h
+++ b/src/heap/incremental-marking.h
@@ -7,6 +7,7 @@
 
 #include "src/cancelable-task.h"
 #include "src/execution.h"
+#include "src/heap/heap.h"
 #include "src/heap/incremental-marking-job.h"
 #include "src/heap/spaces.h"
 #include "src/objects.h"
@@ -153,6 +154,9 @@
   static void RecordWriteFromCode(HeapObject* obj, Object** slot,
                                   Isolate* isolate);
 
+  static void RecordWriteOfCodeEntryFromCode(JSFunction* host, Object** slot,
+                                             Isolate* isolate);
+
   // Record a slot for compaction.  Returns false for objects that are
   // guaranteed to be rescanned or not guaranteed to survive.
   //
@@ -215,10 +219,10 @@
   }
 
  private:
-  class Observer : public InlineAllocationObserver {
+  class Observer : public AllocationObserver {
    public:
     Observer(IncrementalMarking& incremental_marking, intptr_t step_size)
-        : InlineAllocationObserver(step_size),
+        : AllocationObserver(step_size),
           incremental_marking_(incremental_marking) {}
 
     void Step(int bytes_allocated, Address, size_t) override {