bug#25212: REPL aborts when a stack overflow is triggered twice

[Steff]

When a Stack Overflow occured the new prompt of the REPL becomes fragile 
an sometimes crashes on invalid inputs.
A reliant way to make the REPL abort, is by triggering a stack overflow 
twice.

Affected Version: 2.0.13

Way to reproduce:

scheme@(guile-user)> (define x (lambda () (x) (x)))   ;;; define a 
function provoking a stack-overflow
scheme@(guile-user)> (x) (x)                          ;;; first call of 
this function is caught but second aborts the REPL
<unnamed port>:2:0: In procedure x:
<unnamed port>:2:0: Throw to key `vm-error' with args `(vm-run "VM: 
Stack overflow" ())'.

Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
[1]    13794 abort (core dumped)  guile