swig: Warn on use of incompatible swig/gcc combinations
swig: Warn on use of incompatible swig/gcc combinations

This patch removes the fixed swig warning concerning 2.0.9/2.0.10 and
adds a warning message for incompatible combinations of swig and gcc.

andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin