[interpreter] Drop overprotective --harmony-instanceof check.

src/interpreter/bytecode-array-builder.cc

Index: src/interpreter/bytecode-array-builder.cc
diff --git a/src/interpreter/bytecode-array-builder.cc b/src/interpreter/bytecode-array-builder.cc
index c1db0b0ca2317436187c8e468419958aa93ef784..86d973045205cc34160936e0429b051d8068fcac 100644
--- a/src/interpreter/bytecode-array-builder.cc
+++ b/src/interpreter/bytecode-array-builder.cc
@@ -1433,7 +1433,6 @@ Bytecode BytecodeArrayBuilder::BytecodeForCompareOperation(Token::Value op) {
     case Token::Value::GTE:
       return Bytecode::kTestGreaterThanOrEqual;
     case Token::Value::INSTANCEOF:
-      DCHECK(!FLAG_harmony_instanceof);
       return Bytecode::kTestInstanceOf;
     case Token::Value::IN:
       return Bytecode::kTestIn;