[compiler] Drop the CompareNilIC.

src/full-codegen/mips/full-codegen-mips.cc

Index: src/full-codegen/mips/full-codegen-mips.cc
diff --git a/src/full-codegen/mips/full-codegen-mips.cc b/src/full-codegen/mips/full-codegen-mips.cc
index d4e80052fde0469d8ff066aaef69bb4ef0c42cab..1c71e8b4500ba72aa63824b5ce85880110f9d426 100644
--- a/src/full-codegen/mips/full-codegen-mips.cc
+++ b/src/full-codegen/mips/full-codegen-mips.cc
@@ -4004,18 +4004,18 @@ void FullCodeGenerator::EmitLiteralCompareNil(CompareOperation* expr,
 
   VisitForAccumulatorValue(sub_expr);
   PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  __ mov(a0, result_register());
   if (expr->op() == Token::EQ_STRICT) {
     Heap::RootListIndex nil_value = nil == kNullValue ?
         Heap::kNullValueRootIndex :
         Heap::kUndefinedValueRootIndex;
     __ LoadRoot(a1, nil_value);
-    Split(eq, a0, Operand(a1), if_true, if_false, fall_through);
-  } else {
-    Handle<Code> ic = CompareNilICStub::GetUninitialized(isolate(), nil);
-    CallIC(ic, expr->CompareOperationFeedbackId());
-    __ LoadRoot(a1, Heap::kTrueValueRootIndex);
     Split(eq, v0, Operand(a1), if_true, if_false, fall_through);
+  } else {
+    __ JumpIfSmi(v0, if_false);
+    __ lw(v0, FieldMemOperand(v0, HeapObject::kMapOffset));
+    __ lbu(a1, FieldMemOperand(v0, Map::kBitFieldOffset));
+    __ And(a1, a1, Operand(1 << Map::kIsUndetectable));
+    Split(ne, a1, Operand(zero_reg), if_true, if_false, fall_through);
   }
   context()->Plug(if_true, if_false);
 }