[arm64] Add assertions to Claim and Drop.

src/arm64/macro-assembler-arm64.h

Index: src/arm64/macro-assembler-arm64.h
diff --git a/src/arm64/macro-assembler-arm64.h b/src/arm64/macro-assembler-arm64.h
index 56f82b53d3c47834d7226f735ef29d8284de4ed3..628ab6d5b7af8fc1a9f122b46df206785962e589 100644
--- a/src/arm64/macro-assembler-arm64.h
+++ b/src/arm64/macro-assembler-arm64.h
@@ -724,10 +724,10 @@ class MacroAssembler : public Assembler {
   //
   // Note that unit_size must be specified in bytes. For variants which take a
   // Register count, the unit size must be a power of two.
-  inline void Claim(uint64_t count, uint64_t unit_size = kXRegSize);
+  inline void Claim(int64_t count, uint64_t unit_size = kXRegSize);
   inline void Claim(const Register& count,
                     uint64_t unit_size = kXRegSize);
-  inline void Drop(uint64_t count, uint64_t unit_size = kXRegSize);
+  inline void Drop(int64_t count, uint64_t unit_size = kXRegSize);
   inline void Drop(const Register& count,
                    uint64_t unit_size = kXRegSize);
 
@@ -977,6 +977,10 @@ class MacroAssembler : public Assembler {
   // Abort execution if argument is not a string, enabled via --debug-code.
   void AssertString(Register object);
 
+  // Abort execution if argument is not a positive or zero integer, enabled via
+  // --debug-code.
+  void AssertPositiveOrZero(Register value);
+
   void JumpIfHeapNumber(Register object, Label* on_heap_number,
                         SmiCheckType smi_check_type = DONT_DO_SMI_CHECK);
   void JumpIfNotHeapNumber(Register object, Label* on_not_heap_number,