ARM: Use ubfx and movw instructions to avoid a PC-relative load on

src/assembler.h

Index: src/assembler.h
===================================================================
--- src/assembler.h	(revision 10578)
+++ src/assembler.h	(working copy)
@@ -203,6 +203,10 @@
     CODE_TARGET_CONTEXT,  // Code target used for contextual loads and stores.
     DEBUG_BREAK,  // Code target for the debugger statement.
     EMBEDDED_OBJECT,
+#ifdef V8_TARGET_ARCH_ARM
+    // An integer that is shorter than a pointer but uniquely identifies a map.
+    MAP_SIGNATURE,
+#endif
     GLOBAL_PROPERTY_CELL,
 
     // Everything after runtime_entry (inclusive) is not GC'ed.
@@ -213,7 +217,9 @@
     STATEMENT_POSITION,  // See comment for kNoPosition above.
     DEBUG_BREAK_SLOT,  // Additional code inserted for debug break slot.
     EXTERNAL_REFERENCE,  // The address of an external C++ function.
+#ifndef V8_TARGET_ARCH_ARM
     INTERNAL_REFERENCE,  // An address inside the same function.
+#endif
 
     // add more as needed
     // Pseudo-types
@@ -238,6 +244,11 @@
   static inline bool IsCodeTarget(Mode mode) {
     return mode <= LAST_CODE_ENUM;
   }
+#ifdef V8_TARGET_ARCH_ARM
+  static inline bool IsMapSignature(Mode mode) {
+    return mode == MAP_SIGNATURE;
+  }
+#endif
   static inline bool IsEmbeddedObject(Mode mode) {
     return mode == EMBEDDED_OBJECT;
   }
@@ -260,9 +271,11 @@
   static inline bool IsExternalReference(Mode mode) {
     return mode == EXTERNAL_REFERENCE;
   }
+#ifndef V8_TARGET_ARCH_ARM
   static inline bool IsInternalReference(Mode mode) {
     return mode == INTERNAL_REFERENCE;
   }
+#endif
   static inline bool IsDebugBreakSlot(Mode mode) {
     return mode == DEBUG_BREAK_SLOT;
   }