When running the test suite with this patch applied and
"-fno-trampolines", there are some errors. Most of it is expected
(e.g. nested-6.c calls qsort which fails because it has not
itself been compiled with -fno-trampolines).
One test case for __builtin_call_with_static_chain
in gcc.dg/cwsc1.cfa
A while ago Eric Botcazou added support for function descriptors
as a replacement for trampolines. This is used in Ada, but not
in C where it would also imply a change of ABI. Still, as nested
functions are generally not used across interface boundaries,
I thought it would be really useful to ha