[wasm] WIP fix arm64 frame alignment.

src/arm64/macro-assembler-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.
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 1337 matching lines @@
         Abort(kTheCurrentStackPointerIsBelowCsp);
       }
 
       bind(&ok);
       // Restore StackPointer().
       sub(StackPointer(), csp, StackPointer());
     }
   }
 }
 
+void MacroAssembler::AssertCspAligned() {
+  if (emit_debug_code() && use_real_aborts()) {
+    // TODO(titzer): use a real assert for alignment check?
+    UseScratchRegisterScope scope(this);
+    Register temp = scope.AcquireX();
+    ldr(temp, MemOperand(csp));
+  }
+}
 
 void MacroAssembler::AssertFPCRState(Register fpcr) {
   if (emit_debug_code()) {
     Label unexpected_mode, done;
     UseScratchRegisterScope temps(this);
     if (fpcr.IsNone()) {
       fpcr = temps.AcquireX();
       Mrs(fpcr, FPCR);
     }
 
@@ skipping 3703 matching lines @@
 }
 
 
 #undef __
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64