Shadow SIM's debug_printf function

GDB and SIM both have functions called "debug_printf", which conflicts
at link time.  This commit shadows SIM's debug_printf with a macro so
that SIM's symbol ends up being called "sim_debug_printf".

sim/common/ChangeLog:

	* sim-trace.h (debug_printf): New define.

sim/common/ChangeLog

@@ -1,3 +1,7 @@
+2014-08-28  Gary Benson  <gbenson@redhat.com>
+
+	* sim-trace.h (debug_printf): New define.
+
 2014-08-19  Alan Modra  <amodra@gmail.com>
 
 	* configure: Regenerate.

sim/common/sim-trace.h

@@ -583,6 +583,9 @@ extern void trace_vprintf (SIM_DESC, sim_cpu *, const char *, va_list);
 /* Non-zero if "--debug-insn" specified.  */
 #define DEBUG_INSN_P(cpu) DEBUG_P (cpu, DEBUG_INSN_IDX)
 
+/* GDB also has a debug_printf, so we shadow ours.  */
+#define debug_printf sim_debug_printf
+
 extern void debug_printf (sim_cpu *, const char *, ...)
      __attribute__((format (printf, 2, 3)));