Merge a number of assertion failure fixes to the 3.0 branch.

src/x64/full-codegen-x64.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 227 matching lines @@
     // Add a label for checking the size of the code used for returning.
     Label check_exit_codesize;
     masm_->bind(&check_exit_codesize);
 #endif
     CodeGenerator::RecordPositions(masm_, function()->end_position() - 1);
     __ RecordJSReturn();
     // Do not use the leave instruction here because it is too short to
     // patch with the code required by the debugger.
     __ movq(rsp, rbp);
     __ pop(rbp);
-    __ ret((scope()->num_parameters() + 1) * kPointerSize);
+
+    int arguments_bytes = (scope()->num_parameters() + 1) * kPointerSize;
+    __ Ret(arguments_bytes, rcx);
+
 #ifdef ENABLE_DEBUGGER_SUPPORT
     // Add padding that will be overwritten by a debugger breakpoint.  We
-    // have just generated "movq rsp, rbp; pop rbp; ret k" with length 7
+    // have just generated at least 7 bytes: "movq rsp, rbp; pop rbp; ret k"
     // (3 + 1 + 3).
     const int kPadding = Assembler::kJSReturnSequenceLength - 7;
     for (int i = 0; i < kPadding; ++i) {
       masm_->int3();
     }
-    // Check that the size of the code used for returning matches what is
-    // expected by the debugger.
-    ASSERT_EQ(Assembler::kJSReturnSequenceLength,
-            masm_->SizeOfCodeGeneratedSince(&check_exit_codesize));
+    // Check that the size of the code used for returning is large enough
+    // for the debugger's requirements.
+    ASSERT(Assembler::kJSReturnSequenceLength <=
+           masm_->SizeOfCodeGeneratedSince(&check_exit_codesize));
 #endif
   }
 }
 
 
 FullCodeGenerator::ConstantOperand FullCodeGenerator::GetConstantOperand(
     Token::Value op, Expression* left, Expression* right) {
   ASSERT(ShouldInlineSmiCase(op));
   return kNoConstants;
 }
@@ skipping 3373 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64