Remove obsolete field in RelocInfo.

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index 50e9906545520c37d1b196b95c6e5a2af4d9842b..1a3219db1acf93eea3a4615da10ae791d48d107e 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -662,11 +662,6 @@ class RelocInfo {
   Mode rmode_;
   intptr_t data_;
   Code* host_;
-  // External-reference pointers are also split across instruction-pairs
-  // on some platforms, but are accessed via indirect pointers. This location
-  // provides a place for that pointer to exist naturally. Its address
-  // is returned by RelocInfo::target_reference_address().
-  Address reconstructed_adr_ptr_;
   friend class RelocIterator;
 };