wireshark 2.2.x build fail

[Michael Butler]

Just a "heads up": wireshark 2.2.x introduces the compiler flag 
"-msse4.2" via 'configure' if the compiler accepts that flag.

The capability, or otherwise, of the host machine is ignored as it is 
expected that the one module in which GCC will use these instructions 
has a run-time check.

This does not work for CLANG on "deficient" hardware; LEMON (part of the 
build tool-chain) will also be compiled with these extended instructions 
and cause exceptions on hardware that doesn't support them :-(

There's a related discussion on the wireshark-bugs list referring to 
"bug 10792"

	Michael