sim: ppc: align format string settings with common code

This copies logic used in the common sim warning configure code to fix
build errors for mingw targets.  Turning format warnings on triggers
a failure in the debug.c file, so apply a minor fix at the same time.

sim/ppc/configure

@@ -3489,6 +3489,12 @@ sim_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith
 -Wno-pointer-sign
 -Wold-style-declaration -Wold-style-definition
 "
+# Enable -Wno-format by default when using gcc on mingw since many
+# GCC versions complain about %I64.
+case "${host}" in
+  *-*-mingw32*) sim_warnings="$sim_warnings -Wno-format" ;;
+  *) sim_warnings="$sim_warnings -Wformat-nonliteral" ;;
+esac
 # Check whether --enable-sim-warnings was given.
 if test "${enable_sim_warnings+set}" = set; then :
   enableval=$enable_sim_warnings; case "${enableval}" in

sim/ppc/configure.ac

@@ -430,6 +430,12 @@ sim_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith
 -Wno-pointer-sign
 -Wold-style-declaration -Wold-style-definition
 "
+# Enable -Wno-format by default when using gcc on mingw since many
+# GCC versions complain about %I64.
+case "${host}" in
+  *-*-mingw32*) sim_warnings="$sim_warnings -Wno-format" ;;
+  *) sim_warnings="$sim_warnings -Wformat-nonliteral" ;;
+esac
 AC_ARG_ENABLE(sim-warnings,
 [  --enable-sim-warnings=opts		Extra CFLAGS for turning on compiler warnings except for idecode.o, semantics.o and psim.o],
 [case "${enableval}" in

sim/ppc/debug.c

@@ -140,7 +140,7 @@ trace_usage(int verbose)
     printf_filtered("\n");
   }
   if (verbose > 1) {
-    const char *format = "\t%-18s%s\n";
+    static const char format[] = "\t%-18s%s\n";
     int i;
     printf_filtered(format, "all", "enable all the trace options");
     for (i = 0; trace_description[i].option < nr_trace_options; i++)