It reverts commit:
https://sourceforge.net/p/angelscript/code/2278/
It looks that it's impossible to detect "real" clang version using compiler definitions, so that we can't check if std::is_trivially_default_constructible is available.
I mean that clang 4.0 on my machine is "newer" than clang 5.0 on travis, because it tries to use gcc 4.8 headers:
/usr/lib/gcc/*x86_64-linux-gnu/4.8*/../../../../include/c++/4.8/type_traits:1211:12:
note: 'has_trivial_default_constructor' declared here
struct has_trivial_default_constructor
At this stage we can just disable AS_CAN_USE_CPP11 for clang. It was disabled for clang before our angelscript upgrade, so that it's not worse than before.
Note that I don't use clang and I don't really know what are our requirements (for example for Mac OS build). Feel free to revert it after travis upgrade.
