[es6] Don't disable ES6 tail call elimination when Debugger is on.

src/mips/builtins-mips.cc

Index: src/mips/builtins-mips.cc
diff --git a/src/mips/builtins-mips.cc b/src/mips/builtins-mips.cc
index 84af8f12e581301b45c0afc2029b893bd4da0d6c..99226e7da19bc996552abf71aedccd42cc6fd814 100644
--- a/src/mips/builtins-mips.cc
+++ b/src/mips/builtins-mips.cc
@@ -1960,14 +1960,6 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
   Comment cmnt(masm, "[ PrepareForTailCall");
 
-  // Prepare for tail call only if the debugger is not active.
-  Label done;
-  ExternalReference debug_is_active =
-      ExternalReference::debug_is_active_address(masm->isolate());
-  __ li(at, Operand(debug_is_active));
-  __ lb(scratch1, MemOperand(at));
-  __ Branch(&done, ne, scratch1, Operand(zero_reg));
-
   // Drop possible interpreter handler/stub frame.
   {
     Label no_interpreter_frame;
@@ -2011,7 +2003,6 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   ParameterCount callee_args_count(args_reg);
   __ PrepareForTailCall(callee_args_count, caller_args_count_reg, scratch2,
                         scratch3);
-  __ bind(&done);
 }
 }  // namespace