Again, this simplifies the semantic checks and lowering quite a bit.
Update the check for positive alignment to use a more informative
message, and to highlight the modifier itsef, not the whole clause.
Remove the checks for the allocator expression itself being positive:
there is nothing in the spec that says that it should be positive.
Remove the "simple" modifier from the AllocateT template, since both
simple and complex modifiers are the same thing, only differing in
syntax.
cdbd22876b