Fix on stack handling for Arguments

This make sure we also update the receiver and block and handles
arguments better. This way arguments also get updated if they do not
originate from a tuple container.
Also make sure to mark BlockInvocation properties on stack

This makes sure these properties are also updated when we potentially do
a GC.

Found when running #2628
Add missing definition for capi_rfloat_value to headers

Also adds explicit defines that we have rb_time_* functions.

Fixes #2714
Restrict CAPI tests on rb_fix2int and rb_fix2uint to x64 systems.
Restrict CAPI tests on rb_num2int and rb_num2uint to x64 systems.