alloc profile: inline gc_pool_alloc (with another wrapper)

[vilterp]

merges into JuliaLang#43868

This inlines the new shared implementation of jl_gc_pool_alloc into the old callers, so that there's no added overhead from the extra function call.

Changes the graph to this:

*: instrumented; red: currently missed; green: newly introduced function

graphviz

digraph G {
  node [shape=box];

  generated_code [label="<generated code>"];

  new_array;
  jl_gc_alloc_string [label="jl_gc_alloc_string *"];
  jl_gc_alloc [label="jl_gc_alloc *"];
  jl_gc_managed_malloc [label="jl_managed_malloc *"]; // https://github.com/vilterp/julia/pull/20
  jl_gc_pool_alloc;
  jl_gc_pool_alloc [fillcolor=lightgreen style=filled label="jl_gc_pool_alloc *"];
  jl_gc_big_alloc;

  {
    rank=same;
    jl_gc_managed_malloc;
    jl_gc_pool_alloc_inner;
    jl_gc_big_alloc;
  }

  generated_code -> jl_gc_alloc_string;
  generated_code -> new_array;
  generated_code -> jl_gc_alloc;
  generated_code -> jl_gc_big_alloc [color=red];
  generated_code -> jl_gc_pool_alloc;
  jl_gc_pool_alloc -> jl_gc_pool_alloc_inner;

  jl_gc_alloc -> jl_gc_pool_alloc_inner;
  jl_gc_alloc -> jl_gc_big_alloc;
  new_array -> jl_gc_alloc;
  new_array -> jl_gc_managed_malloc;
  jl_gc_alloc_string -> jl_gc_pool_alloc_inner;
  jl_gc_alloc_string -> jl_gc_big_alloc;
}

[NHDaly]

@vtjnash: I know you said you would prefer inlining jl_gc_pool_alloc_inner into all the functions, including jl_gc_pool_alloc and jl_gc_big_alloc, but that proved difficult because that function itself calls some other inline functions defined in the .c file, and all those would need to be extracted into the header file, and it seemed like that would be a nontrivial surgery.

Since this change keeps things the most similar to what they were before our PR, we'd like to do it this way, and then we can evaluate inlining everywhere it in a separate step afterwards if you think that's generally valuable?

i'm gonna approve this now, but it'd probably be good to get your two cents on it, too Jameson! :)

Thanks!