More Chrome tests

Looks like we have an issue as the tests do not pass on most
not-so-old perls. 5.18 is ok.
Chrome: workaround perl < 5.16 bug (inlining+overloading)

Old perls (< 5.16) had an issue in constant inlining combined to
overloading of mathematical operators. The result is that Red+Bold
was inlined into a random number.
The workaround is to not use constant.pm in < 5.16 case, and instead
use closures that will not be inlined.