Blender Git Loki

BLI linkstack macros: do not prepend the 'anti-namespace-collision' to var name.

Issue was, in case of using such stack within a structure, the '_' underscore
would be added in front of struct variable
(e.g. `my_struct.my_stack` would lead to (try to) using `_my_struct.my_var_pool` ...).

Now underscore is appended to var names, ugly but working.

Note did not touch to the alloca variants of those macros, since in this case enforcing
a pure local use is best I think.