Revert "ARM: Improve register allocation and constraints."

src/arm/code-stubs-arm.cc

 // Copyright 2011 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 3523 matching lines @@
 
   // Called from C, so do not pop argc and args on exit (preserve sp)
   // No need to save register-passed args
   // Save callee-saved registers (incl. cp and fp), sp, and lr
   __ stm(db_w, sp, kCalleeSaved | lr.bit());
 
   if (CpuFeatures::IsSupported(VFP3)) {
     CpuFeatures::Scope scope(VFP3);
     // Save callee-saved vfp registers.
     __ vstm(db_w, sp, kFirstCalleeSavedDoubleReg, kLastCalleeSavedDoubleReg);
-    // Set up the reserved register for 0.0.
-    __ vmov(kDoubleRegZero, 0.0);
   }
 
   // Get address of argv, see stm above.
   // r0: code entry
   // r1: function
   // r2: receiver
   // r3: argc
 
   // Setup argv in r4.
   int offset_to_argv = (kNumCalleeSaved + 1) * kPointerSize;
@@ skipping 3047 matching lines @@
   __ mov(result, Operand(0));
   __ Ret();
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM