Revert "ARM64: Use UntagSmi helpers and clean up assertions."

src/arm64/assembler-arm64-inl.h

Index: src/arm64/assembler-arm64-inl.h
diff --git a/src/arm64/assembler-arm64-inl.h b/src/arm64/assembler-arm64-inl.h
index 960fe63fa2c7d6683db053e80995022413fb2944..444f2c4a9455316605d00da9d61a8f2f86ef2fca 100644
--- a/src/arm64/assembler-arm64-inl.h
+++ b/src/arm64/assembler-arm64-inl.h
@@ -430,14 +430,12 @@ unsigned Operand::shift_amount() const {
 
 
 Operand Operand::UntagSmi(Register smi) {
-  STATIC_ASSERT((kSmiShift + kSmiValueSize) == kXRegSizeInBits);
   ASSERT(smi.Is64Bits());
   return Operand(smi, ASR, kSmiShift);
 }
 
 
 Operand Operand::UntagSmiAndScale(Register smi, int scale) {
-  STATIC_ASSERT((kSmiShift + kSmiValueSize) == kXRegSizeInBits);
   ASSERT(smi.Is64Bits());
   ASSERT((scale >= 0) && (scale <= (64 - kSmiValueSize)));
   if (scale > kSmiShift) {