The following is a failure with IMA on fairly basic stuff.  Compile the files together as
cc -O0 -c -o foo.o file1.c file2.c
You get a multiply defined symbol in the .s file.  This goes away with -O2 or higher.

There should probably be an IMA component, I don't think this is the last problem
we'll have with it (and Geoff insists it's not an optimization, so that's inappropriate).

/* file 1 */
char *globals[] = {"a", "b"};
foo() {
  printf("%s\n", globals[0]);
}

/* file 2 */
extern char *globals[];
main() {
  printf("%s\n", globals[1]);
}