No body for 'free' during inlining when using `goto-instrument` with dfcc

[archigup]

When building files with dfcc, and a function exists in the translation unit that calls free, we get an error from goto-instrument.

This was tested with the main branch (commit 062962c).

This affects a lot of our files as we have a header with a static inline function that calls free.

I've minimized a reproducer here:

test.c:

#include <stddef.h>
#include <stdlib.h>

void foo(void) {
    free(NULL);
}

int main(void) {
}

commands to repro:

$ goto-cc test.c -o test.goto 
$ goto-instrument test.goto test.goto --dfcc main
Reading GOTO program from 'test.goto'
Function Pointer Removal
Virtual function removal
Cleaning inline assembler statements
Trying to force one backedge per target
Loading CPROVER C library (x86_64)
Adding the cprover_contracts library (x86_64)
file <builtin-library-malloc> line 6: symbol '__CPROVER_malloc_is_new_array' already has an initial value
symbol '__CPROVER_alloca_object' already has an initial value
symbol '__CPROVER_new_object' already has an initial value
file <builtin-library-free> line 11: symbol '__CPROVER_malloc_is_new_array' already has an initial value
file <builtin-library-__CPROVER_contracts_library> line 1077 function __CPROVER_contracts_write_set_deallocate_freeable: no body for function 'free'
No body for 'free' during inlining
Numeric exception : 0
6$