You will want to add these prints to int_unx.c:
printf ("BFAR = %x\n", (*((volatile unsigned long *)(0xE000ED38))));
printf ("CFSR = %x\n", (*((volatile unsigned long *)(0xE000ED28))));
printf ("HFSR = %x\n", (*((volatile unsigned long *)(0xE000ED2C))));
printf ("DFSR = %x\n", (*((volatile unsigned long *)(0xE000ED30))));
printf ("AFSR = %x\n", (*((volatile unsigned long *)(0xE000ED3C))));
I have found the first 8 words of the first memory dump to generally be the exception stack R0/1/2/3/12/LR/PC/PSP in order.
An apnote to understand it all:
http://www.keil.com/appnotes/files/apnt209.pdf