[strong] Function arity check should be based on required parameters

src/arm64/builtins-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/codegen.h"
 #include "src/debug.h"
@@ skipping 1722 matching lines @@
 
   {  // Too few parameters: Actual < expected
     __ Bind(&too_few);
 
     Register copy_from = x10;
     Register copy_end = x11;
     Register copy_to = x12;
     Register scratch1 = x13, scratch2 = x14;
 
     // If the function is strong we need to throw an error.
-    Label weak_function;
+    Label no_strong_error;
     __ Ldr(scratch1,
            FieldMemOperand(function, JSFunction::kSharedFunctionInfoOffset));
     __ Ldr(scratch2.W(),
            FieldMemOperand(scratch1, SharedFunctionInfo::kCompilerHintsOffset));
     __ TestAndBranchIfAllClear(scratch2.W(),
                                (1 << SharedFunctionInfo::kStrongModeFunction),
-                               &weak_function);
+                               &no_strong_error);
+
+    // What we really care about is the required number of arguments.
+    DCHECK_EQ(kPointerSize, kInt64Size);
+    __ Ldr(scratch2.W(),
+           FieldMemOperand(scratch1, SharedFunctionInfo::kLengthOffset));
+    __ Cmp(argc_actual, Operand(scratch2, LSR, 1));
+    __ B(ge, &no_strong_error);
 
     {
       FrameScope frame(masm, StackFrame::MANUAL);
       EnterArgumentsAdaptorFrame(masm);
       __ CallRuntime(Runtime::kThrowStrongModeTooFewArguments, 0);
     }
 
-    __ bind(&weak_function);
+    __ Bind(&no_strong_error);
     EnterArgumentsAdaptorFrame(masm);
 
     __ Lsl(argc_expected, argc_expected, kPointerSizeLog2);
     __ Lsl(argc_actual, argc_actual, kPointerSizeLog2);
 
     // Adjust for fp, lr, and the receiver.
     __ Add(copy_from, fp, 3 * kPointerSize);
     __ Add(copy_from, copy_from, argc_actual);
     __ Mov(copy_to, jssp);
     __ Sub(copy_end, copy_to, 1 * kPointerSize);   // Adjust for the receiver.
@@ skipping 55 matching lines @@
     __ Unreachable();
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM