Fixed assertions on ARM64.

src/arm64/macro-assembler-arm64-inl.h

Index: src/arm64/macro-assembler-arm64-inl.h
diff --git a/src/arm64/macro-assembler-arm64-inl.h b/src/arm64/macro-assembler-arm64-inl.h
index 38b5d4b7518fc705f184ec38137f1c3004e8d650..06bcd112af7a93d8d2163d836575cfb409553c4d 100644
--- a/src/arm64/macro-assembler-arm64-inl.h
+++ b/src/arm64/macro-assembler-arm64-inl.h
@@ -1532,7 +1532,7 @@ void MacroAssembler::Claim(const Register& count, uint64_t unit_size) {
 
 
 void MacroAssembler::ClaimBySMI(const Register& count_smi, uint64_t unit_size) {
-  ASSERT(IsPowerOf2(unit_size));
+  ASSERT(unit_size == 0 || IsPowerOf2(unit_size));
   const int shift = CountTrailingZeros(unit_size, kXRegSizeInBits) - kSmiShift;
   const Operand size(count_smi,
                      (shift >= 0) ? (LSL) : (LSR),
@@ -1593,7 +1593,7 @@ void MacroAssembler::Drop(const Register& count, uint64_t unit_size) {
 
 
 void MacroAssembler::DropBySMI(const Register& count_smi, uint64_t unit_size) {
-  ASSERT(IsPowerOf2(unit_size));
+  ASSERT(unit_size == 0 || IsPowerOf2(unit_size));
   const int shift = CountTrailingZeros(unit_size, kXRegSizeInBits) - kSmiShift;
   const Operand size(count_smi,
                      (shift >= 0) ? (LSL) : (LSR),