Backport hash collision workaround to 3.6.

src/arm/builtins-arm.cc

Index: src/arm/builtins-arm.cc
===================================================================
--- src/arm/builtins-arm.cc	(revision 10353)
+++ src/arm/builtins-arm.cc	(working copy)
@@ -1006,10 +1006,7 @@
   // Set up the context from the function argument.
   __ ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
 
-  // Set up the roots register.
-  ExternalReference roots_address =
-      ExternalReference::roots_address(masm->isolate());
-  __ mov(r10, Operand(roots_address));
+  __ InitializeRootRegister();
 
   // Push the function and the receiver onto the stack.
   __ push(r1);