[PATCH] ia64: pass si_isr for a few more signal sources

This patch changes the kernel such that si_isr gets setup for hardware
breakpoints, single-step, and taken-branch traps.  This is useful, e.g., to
determine what kind of hw breakpoint triggered the signal.

arch/ia64/kernel/traps.c

@@ -568,10 +568,10 @@ ia64_fault (unsigned long vector, unsigned long isr, unsigned long ifa,
 		}
 		siginfo.si_signo = SIGTRAP;
 		siginfo.si_errno = 0;
-		siginfo.si_flags = 0;
-		siginfo.si_isr = 0;
 		siginfo.si_addr  = (void *) ifa;
 		siginfo.si_imm   = 0;
+		siginfo.si_flags = __ISR_VALID;
+		siginfo.si_isr   = isr;
 		force_sig_info(SIGTRAP, &siginfo, current);
 		return;