beflags, ia32: Use the correct Proj num of the new flags producer.

Also remove the nonsensical parameter pn, which is the Proj num of the old flags producer, from the try_replace callback.

ir/be/beflags.c

@@ -58,12 +58,11 @@ static bool default_check_modifies(const ir_node *node)
 	return arch_irn_is(node, modify_flags);
 }
 
-static bool default_try_replace(ir_node *consumers, ir_node *flags, ir_node *available, unsigned pn)
+static bool default_try_replace(ir_node *consumers, ir_node *flags, ir_node *available)
 {
 	(void)consumers;
 	(void)flags;
 	(void)available;
-	(void)pn;
 	return false;
 }
 
@@ -152,10 +151,8 @@ static bool rematerialize_or_move(ir_node *flags_needed, ir_node *node,
 	}
 
 	/* Try to use the flags available at this point. */
-	if (available_flags != NULL &&
-	    try_replace(flag_consumers, flags_needed, available_flags, pn)) {
+	if (available_flags && try_replace(flag_consumers, flags_needed, available_flags))
 		return true;
-	}
 
 	changed = true;
 	ir_node *copy = remat(flags_needed, node);

ir/be/beflags.h

@@ -27,7 +27,7 @@ typedef bool (*check_modifies_flags) (const ir_node *node);
  * Callback function that checks whether consumers can use the
  * available flags instead of their original ones.
  */
-typedef bool (*try_replace_flags) (ir_node *consumers, ir_node *flags_needed, ir_node *available_flags, unsigned pn);
+typedef bool (*try_replace_flags) (ir_node *consumers, ir_node *flags_needed, ir_node *available_flags);
 
 /**
  * Walks the schedule and ensures that flags aren't destroyed between producer

ir/be/ia32/bearch_ia32.c

@@ -555,13 +555,18 @@ COMPILETIME_ASSERT((int)(n_ia32_Sub_minuend)    == (int)(n_ia32_Cmp_left) &&
                    (int)(n_ia32_Sub_subtrahend) == (int)(n_ia32_Cmp_right),
                    Cmp_and_Sub_operand_numbers_equal)
 
-static bool ia32_try_replace_flags(ir_node *consumers, ir_node *flags, ir_node *available, unsigned pn)
+static bool ia32_try_replace_flags(ir_node *consumers, ir_node *flags, ir_node *available)
 {
 	if (!is_ia32_Sub(flags) && !is_ia32_Cmp(flags))
 		return false;
-	if (!is_ia32_Sub(available) && !is_ia32_Cmp(available))
+	unsigned pn;
+	if (is_ia32_Sub(available)) {
+		pn = pn_ia32_Sub_flags;
+	} else if (is_ia32_Cmp(available)) {
+		pn = pn_ia32_Cmp_eflags;
+	} else {
 		return false;
-
+	}
 	/* Assuming CSE would have found the more obvious case */
 	ir_node *const flags_left  = get_irn_n(flags,     n_ia32_binary_left);
 	ir_node *const avail_right = get_irn_n(available, n_ia32_binary_right);