Remove --experimental-classes flag and related dead code.

src/mips64/full-codegen-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.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_MIPS64
 
 // Note on Mips implementation:
 //
@@ skipping 422 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
     // Make sure that the constant pool is not emitted inside of the return
     // sequence.
     { Assembler::BlockTrampolinePoolScope block_trampoline_pool(masm_);
       // Here we use masm_-> instead of the __ macro to avoid the code coverage
       // tool from instrumenting as we rely on the code size here.
       int32_t arg_count = info_->scope()->num_parameters() + 1;
-      if (FLAG_experimental_classes &&
-          IsSubclassConstructor(info_->function()->kind())) {
+      if (IsSubclassConstructor(info_->function()->kind())) {
         arg_count++;
       }
       int32_t sp_delta = arg_count * kPointerSize;
       CodeGenerator::RecordPositions(masm_, function()->end_position() - 1);
       __ RecordJSReturn();
       masm_->mov(sp, fp);
       int no_frame_start = masm_->pc_offset();
       masm_->MultiPop(static_cast<RegList>(fp.bit() | ra.bit()));
       masm_->Daddu(sp, sp, Operand(sp_delta));
       masm_->Jump(ra);
@@ skipping 2699 matching lines @@
         PreservePositionScope scope(masm()->positions_recorder());
         VisitForStackValue(property->obj());
       }
       if (is_named_call) {
         EmitCallWithLoadIC(expr);
       } else {
         EmitKeyedCallWithLoadIC(expr, property->key());
       }
     }
   } else if (call_type == Call::SUPER_CALL) {
-    if (FLAG_experimental_classes) {
-      EmitSuperConstructorCall(expr);
-    } else {
-      EmitLoadSuperConstructor();
-      __ Push(result_register());
-      SuperReference* super_ref = callee->AsSuperReference();
-      VisitForStackValue(super_ref->this_var());
-      EmitCall(expr, CallICState::METHOD);
-    }
+    EmitSuperConstructorCall(expr);
   } else {
     DCHECK(call_type == Call::OTHER_CALL);
     // Call to an arbitrary expression not handled specially above.
     { PreservePositionScope scope(masm()->positions_recorder());
       VisitForStackValue(callee);
     }
     __ LoadRoot(a1, Heap::kUndefinedValueRootIndex);
     __ push(a1);
     // Emit function call.
     EmitCall(expr);
@@ skipping 2254 matching lines @@
       Assembler::target_address_at(pc_immediate_load_address)) ==
          reinterpret_cast<uint64_t>(
              isolate->builtins()->OsrAfterStackCheck()->entry()));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS64