[Interpreter] Add support for parameter variables.

src/mips64/builtins-mips64.cc

 // Copyright 2012 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_MIPS64
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 975 matching lines @@
   // TODO(rmcilroy): List of things not currently dealt with here but done in
   // fullcodegen's EmitReturnSequence.
   //  - Supporting FLAG_trace for Runtime::TraceExit.
   //  - Support profiler (specifically decrementing profiling_counter
   //    appropriately and calling out to HandleInterrupts if necessary).
 
   // The return value is in accumulator, which is already in v0.
 
   // Leave the frame (also dropping the register file).
   __ LeaveFrame(StackFrame::JAVA_SCRIPT);
-  // Drop receiver + arguments.
-  __ Drop(1);  // TODO(rmcilroy): Get number of arguments from BytecodeArray.
+
+  // Drop receiver + arguments and return.
+  __ lw(at, FieldMemOperand(kInterpreterBytecodeArrayRegister,
+                            BytecodeArray::kParameterSizeOffset));
+  __ Daddu(sp, sp, at);
   __ Jump(ra);
 }
 
 
 void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
   CallRuntimePassFunction(masm, Runtime::kCompileLazy);
   GenerateTailCallToReturnedCode(masm);
 }
 
 
@@ skipping 866 matching lines @@
   }
 }
 
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS64