MIPS: Deprecate FACTORY helper macro.

Port r14931 (a914442)

Original commit message:
This removes the FACTORY helper macro to avoid accidental TLS access
when using the factory. Most internal code has access to the Isolate by
now whereas tests which are not performance critical still heavily use
TLS access through explicit Isolate::Current() calls.

BUG=

Review URL: https://codereview.chromium.org/15994011
Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14942 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/code-stubs-mips.cc

@@ -961,7 +961,7 @@ static void EmitIdenticalObjectComparison(MacroAssembler* masm,
 
   __ li(exp_mask_reg, Operand(HeapNumber::kExponentMask));
 
-  // Test for NaN. Sadly, we can't just compare to factory->nan_value(),
+  // Test for NaN. Sadly, we can't just compare to Factory::nan_value(),
   // so we do the second best thing - test it ourselves.
   // They are both equal and they are not both Smis so both of them are not
   // Smis. If it's not a heap number, then return equal.

src/mips/full-codegen-mips.cc

@@ -3039,7 +3039,7 @@ void FullCodeGenerator::EmitIsStringWrapperSafeForDefaultValueOf(
   // string "valueOf" the result is false.
   // The use of t2 to store the valueOf string assumes that it is not otherwise
   // used in the loop below.
-  __ li(t2, Operand(FACTORY->value_of_string()));
+  __ li(t2, Operand(isolate()->factory()->value_of_string()));
   __ jmp(&entry);
   __ bind(&loop);
   __ lw(a3, MemOperand(t0, 0));

src/mips/regexp-macro-assembler-mips.cc

@@ -929,9 +929,8 @@ Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
 
   CodeDesc code_desc;
   masm_->GetCode(&code_desc);
-  Handle<Code> code = FACTORY->NewCode(code_desc,
-                                       Code::ComputeFlags(Code::REGEXP),
-                                       masm_->CodeObject());
+  Handle<Code> code = isolate()->factory()->NewCode(
+      code_desc, Code::ComputeFlags(Code::REGEXP), masm_->CodeObject());
   LOG(Isolate::Current(), RegExpCodeCreateEvent(*code, *source));
   return Handle<HeapObject>::cast(code);
 }