Fix a sign-compare error to make gcc 4.9.2 happy.

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 9bc634ef94cd538b541186177e19c56c5b30e53e..e0bc03c9f997a26691c728df7a374ae12ba4969d 100644
--- a/src/interpreter/bytecode-array-builder.cc
+++ b/src/interpreter/bytecode-array-builder.cc
@@ -76,7 +76,8 @@ Handle<BytecodeArray> BytecodeArrayBuilder::ToBytecodeArray() {
 
 template <size_t N>
 void BytecodeArrayBuilder::Output(uint8_t(&bytes)[N]) {
-  DCHECK_EQ(Bytecodes::NumberOfOperands(Bytecodes::FromByte(bytes[0])), N - 1);
+  DCHECK_EQ(Bytecodes::NumberOfOperands(Bytecodes::FromByte(bytes[0])),
+            static_cast<int>(N) - 1);
   last_bytecode_start_ = bytecodes()->size();
   for (int i = 1; i < static_cast<int>(N); i++) {
     DCHECK(OperandIsValid(Bytecodes::FromByte(bytes[0]), i - 1, bytes[i]));