* ggc-page.c (G.context_depth_allocations): New.
        (G.context_depth_collections): New.
        (alloc_page): Set G.context_depth_allocations.
        (ggc_collect): Set G.context_depth_collections.
        (ggc_push_context): Limit to HOST_BITS_PER_LONG contexts.
        (ggc_pop_context): Early exit for no allocations or collections.

From-SVN: r62152