Remove strong mode support from rest argument creation.

src/full-codegen/mips64/full-codegen-mips64.cc

Index: src/full-codegen/mips64/full-codegen-mips64.cc
diff --git a/src/full-codegen/mips64/full-codegen-mips64.cc b/src/full-codegen/mips64/full-codegen-mips64.cc
index 3f82c6371b60db12c2adf55253583fcbd95bd126..03133e150ff7e55819c50cb40f9d7851d5a9e506 100644
--- a/src/full-codegen/mips64/full-codegen-mips64.cc
+++ b/src/full-codegen/mips64/full-codegen-mips64.cc
@@ -282,9 +282,6 @@ void FullCodeGenerator::Generate() {
              Operand(StandardFrameConstants::kCallerSPOffset + offset));
     __ li(RestParamAccessDescriptor::rest_parameter_index(),
           Operand(Smi::FromInt(rest_index)));
-    __ li(RestParamAccessDescriptor::language_mode(),
-          Operand(Smi::FromInt(language_mode())));
-    DCHECK(a1.is(RestParamAccessDescriptor::language_mode()));
     function_in_register_a1 = false;
 
     RestParamAccessStub stub(isolate());