PPC: [compiler] Remove broken support for undetectable strings.

src/ppc/lithium-codegen-ppc.cc

 // Copyright 2014 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/base/bits.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/cpu-profiler.h"
 #include "src/hydrogen-osr.h"
 #include "src/ic/ic.h"
@@ skipping 5885 matching lines @@
   Factory* factory = isolate()->factory();
   if (String::Equals(type_name, factory->number_string())) {
     __ JumpIfSmi(input, true_label);
     __ LoadP(scratch, FieldMemOperand(input, HeapObject::kMapOffset));
     __ CompareRoot(scratch, Heap::kHeapNumberMapRootIndex);
     final_branch_condition = eq;
 
   } else if (String::Equals(type_name, factory->string_string())) {
     __ JumpIfSmi(input, false_label);
     __ CompareObjectType(input, scratch, no_reg, FIRST_NONSTRING_TYPE);
-    __ bge(false_label);
-    __ lbz(scratch, FieldMemOperand(scratch, Map::kBitFieldOffset));
-    __ ExtractBit(r0, scratch, Map::kIsUndetectable);
-    __ cmpi(r0, Operand::Zero());
-    final_branch_condition = eq;
+    final_branch_condition = lt;
 
   } else if (String::Equals(type_name, factory->symbol_string())) {
     __ JumpIfSmi(input, false_label);
     __ CompareObjectType(input, scratch, no_reg, SYMBOL_TYPE);
     final_branch_condition = eq;
 
   } else if (String::Equals(type_name, factory->boolean_string())) {
     __ CompareRoot(input, Heap::kTrueValueRootIndex);
     __ beq(true_label);
     __ CompareRoot(input, Heap::kFalseValueRootIndex);
@@ skipping 367 matching lines @@
   __ Push(scope_info);
   __ push(ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 }  // namespace internal
 }  // namespace v8