[WIP] Initial CallFunctionCallback builtin.

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 59b2e249672376b2b3e8bca48fc6fc47fdbb43f0..d0b7f45374d0ef6d941deb7f50311e771c61525b 100644
--- a/src/arm64/macro-assembler-arm64.cc
+++ b/src/arm64/macro-assembler-arm64.cc
@@ -1688,6 +1688,33 @@ void MacroAssembler::AssertUndefinedOrAllocationSite(Register object,
   }
 }
 
+void MacroAssembler::AssertApiCallResult(Register object) {
+  if (emit_debug_code()) {
+    Label done_checking;
+    Push(object);
+
+    // Check for Smis.
+    JumpIfSmi(object, &done_checking);
+
+    // Check for valid Oddballs.
+    JumpIfRoot(object, Heap::kTrueValueRootIndex, &done_checking);
+    JumpIfRoot(object, Heap::kFalseValueRootIndex, &done_checking);
+    JumpIfRoot(object, Heap::kNullValueRootIndex, &done_checking);
+    JumpIfRoot(object, Heap::kUndefinedValueRootIndex, &done_checking);
+
+    // Check for other primitives (String, Symbol and HeapNumber).
+    STATIC_ASSERT(LAST_PRIMITIVE_TYPE == ODDBALL_TYPE);
+    CompareObjectType(object, object, object, LAST_PRIMITIVE_TYPE);
+    B(lo, &done_checking);
+
+    // Check for JSReceivers.
+    Cmp(object, FIRST_JS_RECEIVER_TYPE);
+    Check(hs, kAPICallReturnedInvalidObject);
+
+    Bind(&done_checking);
+    Pop(object);
+  }
+}
 
 void MacroAssembler::AssertPositiveOrZero(Register value) {
   if (emit_debug_code()) {