MIPS: cleanup api callbacks now that handles are never returned directly

src/mips/macro-assembler-mips.cc

Index: src/mips/macro-assembler-mips.cc
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index 14a1e2fdca778e5a970cd1e65ac4a9918256a19e..ace7323ee9d410cb67f23c6a210910f0e69afd65 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -3963,7 +3963,6 @@ void MacroAssembler::CallApiFunctionAndReturn(ExternalReference function,
                                               ExternalReference thunk_ref,
                                               Register thunk_last_arg,
                                               int stack_space,
-                                              bool returns_handle,
                                               int return_value_offset_from_fp) {
   ExternalReference next_address =
       ExternalReference::handle_scope_next_address(isolate());
@@ -3992,14 +3991,6 @@ void MacroAssembler::CallApiFunctionAndReturn(ExternalReference function,
     PopSafepointRegisters();
   }
 
-  // The O32 ABI requires us to pass a pointer in a0 where the returned struct
-  // (4 bytes) will be placed. This is also built into the Simulator.
-  // Set up the pointer to the returned value (a0). It was allocated in
-  // EnterExitFrame.
-  if (returns_handle) {
-    addiu(a0, fp, ExitFrameConstants::kStackSpaceOffset);
-  }
-
   Label profiler_disabled;
   Label end_profiler_check;
   bool* is_profiling_flag =
@@ -4039,19 +4030,6 @@ void MacroAssembler::CallApiFunctionAndReturn(ExternalReference function,
   Label leave_exit_frame;
   Label return_value_loaded;
 
-  if (returns_handle) {
-    Label load_return_value;
-
-    // As mentioned above, on MIPS a pointer is returned - we need to
-    // dereference it to get the actual return value (which is also a pointer).
-    lw(v0, MemOperand(v0));
-
-    Branch(&load_return_value, eq, v0, Operand(zero_reg));
-    // Dereference returned value.
-    lw(v0, MemOperand(v0));
-    Branch(&return_value_loaded);
-    bind(&load_return_value);
-  }
   // Load value from ReturnValue.
   lw(v0, MemOperand(fp, return_value_offset_from_fp*kPointerSize));
   bind(&return_value_loaded);