ARM backend support for pld (preload data) instruction

src/arm/assembler-arm.h

Index: src/arm/assembler-arm.h
===================================================================
--- src/arm/assembler-arm.h	(revision 13713)
+++ src/arm/assembler-arm.h	(working copy)
@@ -941,6 +941,9 @@
   void mrs(Register dst, SRegister s, Condition cond = al);
   void msr(SRegisterFieldMask fields, const Operand& src, Condition cond = al);
 
+  // Preload data instruction
+  void pld(const MemOperand& src);
+
   // Load/Store instructions
   void ldr(Register dst, const MemOperand& src, Condition cond = al);
   void str(Register src, const MemOperand& dst, Condition cond = al);