Fix missing header issue -- INT_MAX is defined in limits.h. I chose to use a…

Fix missing header issue -- INT_MAX is defined in limits.h.  I chose to use a different constant rather than add the #include.

src/google/protobuf/io/coded_stream.h

@@ -1044,7 +1044,7 @@ inline CodedInputStream::CodedInputStream(ZeroCopyInputStream* input)
     last_tag_(0),
     legitimate_message_end_(false),
     aliasing_enabled_(false),
-    current_limit_(INT_MAX),
+    current_limit_(kint32max),
     buffer_size_after_limit_(0),
     total_bytes_limit_(kDefaultTotalBytesLimit),
     total_bytes_warning_threshold_(kDefaultTotalBytesWarningThreshold),