Invalid string format exception

[jhavrane]

Issue

Found a program which triggers message with invalid format string, as mentioned in #4141.

Compiler bug triggered, please report this error:
exception type: boost::wrapexcept<boost::io::bad_format_string>
error: boost::bad_format_string: format-string is ill-formed

P4 program

#include <core.p4>

extern main {}