Out-of-memory situations raise exceptions instead of aborting

Out-of-memory situations raise exceptions instead of aborting

* libguile/gc.c (scm_oom_fn, scm_init_gc): Install an out-of-memory
  handler that raises an unwind-only out-of-memory exception.
  (scm_gc_warn_proc, scm_init_gc): Install a warning proc that tries to
  print to the current warning port, if the current warning port is a
  file port.
  (scm_gc_after_nonlocal_exit): New interface.  Should be called after a
  nonlocal return to potentially collect memory; otherwise allocations
  could try to expand again when they should collect.

* libguile/continuations.c (scm_i_make_continuation):
* libguile/eval.c (eval):
* libguile/throw.c (catch):
* libguile/vm.c (scm_call_n): Call scm_gc_after_nonlocal_exit after
  nonlocal returns.

* libguile/throw.c (abort_to_prompt, throw_without_pre_unwind): Rework
  to avoid allocating memory.
  (scm_report_out_of_memory): New interface.
  (scm_init_throw): Pre-allocate the arguments for stack-overflow and
  out-of-memory errors.

* module/ice-9/boot-9.scm: Add an out-of-memory exception printer.
* module/system/repl/error-handling.scm (call-with-error-handling): Add
  out-of-memory to the report-keys set.

* libguile/gc-malloc.c (scm_realloc): Call scm_report_out_of_memory if
  realloc fails.

* libguile/error.h:
* libguile/error.c:
* libguile/deprecated.h:
* libguile/deprecated.c (scm_memory_error): Deprecate.

* test-suite/standalone/Makefile.am:
* test-suite/standalone/test-out-of-memory: New test case.