Add knowledge of type_trait bulitins added in gcc 407.

Test failures in meta.unary.prop from 13 -> 7 using gcc4.8

Change-Id: I8b44d8e2bc24977f1e89c3aba9e19e64181a2174
Merge pull request #134 from awong-dev/support-gcc47-typetraits

Support gcc47 typetraits