[intrinsics] Remove the %_IsDate intrinsic.

src/full-codegen/mips/full-codegen-mips.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.
 
 #if V8_TARGET_ARCH_MIPS
 
 // Note on Mips implementation:
 //
 // The result_register() for mips is the 'v0' register, which is defined
 // by the ABI to contain function return values. However, the first
@@ skipping 3155 matching lines @@
   __ GetObjectType(v0, a1, a1);
   __ Branch(&done, ne, a1, Operand(JS_VALUE_TYPE));
 
   __ lw(v0, FieldMemOperand(v0, JSValue::kValueOffset));
 
   __ bind(&done);
   context()->Plug(v0);
 }
 
 
-void FullCodeGenerator::EmitIsDate(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK_EQ(1, args->length());
-
-  VisitForAccumulatorValue(args->at(0));
-
-  Label materialize_true, materialize_false;
-  Label* if_true = nullptr;
-  Label* if_false = nullptr;
-  Label* fall_through = nullptr;
-  context()->PrepareTest(&materialize_true, &materialize_false, &if_true,
-                         &if_false, &fall_through);
-
-  __ JumpIfSmi(v0, if_false);
-  __ GetObjectType(v0, a1, a1);
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(eq, a1, Operand(JS_DATE_TYPE), if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitOneByteSeqStringSetChar(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK_EQ(3, args->length());
 
   Register string = v0;
   Register index = a1;
   Register value = a2;
 
   VisitForStackValue(args->at(0));        // index
   VisitForStackValue(args->at(1));        // value
@@ skipping 1345 matching lines @@
          reinterpret_cast<uint32_t>(
              isolate->builtins()->OsrAfterStackCheck()->entry()));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS