[runtime] Introduce dedicated JSBoundFunction to represent bound functions.

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 8a14ea492af0c37b62c1e5c53445c81943f2f2a9..3e222091f155ac6b7bab2cbc2b1be76386a1b73a 100644
--- a/src/arm64/macro-assembler-arm64.h
+++ b/src/arm64/macro-assembler-arm64.h
@@ -966,6 +966,10 @@ class MacroAssembler : public Assembler {
   // Abort execution if argument is not a JSFunction, enabled via --debug-code.
   void AssertFunction(Register object);
 
+  // Abort execution if argument is not a JSBoundFunction,
+  // enabled via --debug-code.
+  void AssertBoundFunction(Register object);
+
   // Abort execution if argument is not undefined or an AllocationSite, enabled
   // via --debug-code.
   void AssertUndefinedOrAllocationSite(Register object, Register scratch);