Add some more warnings when building with Sun^WOracle's C compiler.

Change-Id: I696b0757ba7fece61f50ebcee79b576a4f15660f
Reviewed-on: https://code.wireshark.org/review/8361
Reviewed-by: Guy Harris <guy@alum.mit.edu>

configure.ac

@@ -1296,6 +1296,13 @@ else
 		CXXFLAGS="+O2 $CFLAGS"
 		AC_MSG_RESULT(HP ANSI C compiler - added -Ae +O2)
 		;;
+	solaris*)
+		#
+		# Crank up the warning level.
+		#
+		CFLAGS="$CFLAGS -v"
+		CXXFLAGS="$CXXFLAGS +w2"
+		;;
 	*)
 		AC_MSG_RESULT(none needed)
 		;;