[Bug tree-optimization/95565] [Feature request] add a flag to only instrument function entry.

[hiraditya at msn dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95565

--- Comment #1 from AK <hiraditya at msn dot com> ---
I believe we need to conditionally disable the following code, but I'm not sure
of all the implications. If someone can implement it that'd be great.

```
gcc/gimplify.c   Around Line:14997

      x = builtin_decl_implicit (BUILT_IN_RETURN_ADDRESS);
      call = gimple_build_call (x, 1, integer_zero_node);
      tmp_var = create_tmp_var (ptr_type_node, "return_addr");
      gimple_call_set_lhs (call, tmp_var);
      gimplify_seq_add_stmt (&cleanup, call);
      x = builtin_decl_implicit (BUILT_IN_PROFILE_FUNC_EXIT);
      call = gimple_build_call (x, 2, this_fn_addr, tmp_var);
      gimplify_seq_add_stmt (&cleanup, call);
      tf = gimple_build_try (seq, cleanup, GIMPLE_TRY_FINALLY);


```