Remove variadic functions, which are slow.

Since these functions are on the fast path, they should be doing actual
arity dispatching, instead of taking varargs and destructuring them.
Remove most common reflection warnings.

For definline, you have to hint parameters two different ways, because
the function gets evaluated/defined two different ways. So a normal
"function-like" typehint in the arglist, and then a "macro-like"
typehint in the function body.
Get rid of spurious/impossible fallback clause
Fix typehint: should be fully qualified
Improved conditional compilation for 1.2.x.

Use a macro to conditionally compile, rather than Class/forName at runtime.
Remove duplication in number-dispatch.

This way 1.2-compat code can't get out of sync with current code.
Merge remote-tracking branch 'amalloy/master'
80-character line cleanup
bump data.json for benchmarking to 0.2.2