Fix test-hashing after recent changes to string hashing.

src/arm/builtins-arm.cc

 // Copyright 2012 the V8 project authors. 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.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1064 matching lines @@
   // Clear the context before we push it when entering the internal frame.
   __ mov(cp, Operand(0, RelocInfo::NONE));
 
   // Enter an internal frame.
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
 
     // Set up the context from the function argument.
     __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
 
-    // Set up the roots register.
-    ExternalReference roots_array_start =
-        ExternalReference::roots_array_start(masm->isolate());
-    __ mov(r10, Operand(roots_array_start));
+    __ InitializeRootRegister();
 
     // Push the function and the receiver onto the stack.
     __ push(r1);
     __ push(r2);
 
     // Copy arguments to the stack in a loop.
     // r1: function
     // r3: argc
     // r4: argv, i.e. points to first arg
     Label loop, entry;
@@ skipping 675 matching lines @@
   __ bind(&dont_adapt_arguments);
   __ Jump(r3);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM