[runtime] Introduce dedicated JSBoundFunction to represent bound functions.

src/arm64/macro-assembler-arm64.cc

Index: src/arm64/macro-assembler-arm64.cc
diff --git a/src/arm64/macro-assembler-arm64.cc b/src/arm64/macro-assembler-arm64.cc
index 32c5a8b3ff6dbc23bbbb6bcb4fb6a2f55ade5d3f..819f2973e2309fbeb94c5728b88ca5e9565b927d 100644
--- a/src/arm64/macro-assembler-arm64.cc
+++ b/src/arm64/macro-assembler-arm64.cc
@@ -1626,6 +1626,19 @@ void MacroAssembler::AssertFunction(Register object) {
 }
 
 
+void MacroAssembler::AssertBoundFunction(Register object) {
+  if (emit_debug_code()) {
+    AssertNotSmi(object, kOperandIsASmiAndNotABoundFunction);
+
+    UseScratchRegisterScope temps(this);
+    Register temp = temps.AcquireX();
+
+    CompareObjectType(object, temp, temp, JS_BOUND_FUNCTION_TYPE);
+    Check(eq, kOperandIsNotABoundFunction);
+  }
+}
+
+
 void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
                                                      Register scratch) {
   if (emit_debug_code()) {