api: Remove set_irn_op() from the public API.

There is no legitimate reason for an outside user to change the op of a node.
Even internally it should be used less, i.e. only for Deleted, Id and Tuple.

include/libfirm/irnode.h

@@ -126,8 +126,6 @@ FIRM_API void set_irn_mode(ir_node *node, ir_mode *mode);
 FIRM_API ir_mode *get_irn_mode(const ir_node *node);
 /** Returns the opcode struct of the node. */
 FIRM_API ir_op *get_irn_op(const ir_node *node);
-/** Sets the opcode struct of the node. */
-FIRM_API void set_irn_op(ir_node *node, ir_op *op);
 /** Returns the opcode-enum of the node. */
 FIRM_API unsigned get_irn_opcode(const ir_node *node);
 /** Returns the string representation of the opcode. */

ir/ir/irnode.c

@@ -318,11 +318,6 @@ ir_op *(get_irn_op)(const ir_node *node)
 	return get_irn_op_(node);
 }
 
-void (set_irn_op)(ir_node *node, ir_op *op)
-{
-	set_irn_op_(node, op);
-}
-
 unsigned (get_irn_opcode)(const ir_node *node)
 {
 	return get_irn_opcode_(node);

ir/ir/irnode_t.h

@@ -27,7 +27,6 @@
 #define get_irn_irg(node)                     get_irn_irg_(node)
 #define get_nodes_block(node)                 get_nodes_block_(node)
 #define get_irn_op(node)                      get_irn_op_(node)
-#define set_irn_op(node, op)                  set_irn_op_(node, op)
 #define get_irn_opcode(node)                  get_irn_opcode_(node)
 #define get_irn_visited(node)                 get_irn_visited_(node)
 #define set_irn_visited(node, v)              set_irn_visited_(node, v)
@@ -110,7 +109,10 @@ static inline ir_op *get_irn_op_(const ir_node *node)
 	return node->op;
 }
 
-static inline void set_irn_op_(ir_node *node, ir_op *op)
+/**
+ * Sets the opcode struct of the node.
+ */
+static inline void set_irn_op(ir_node *node, ir_op *op)
 {
 	node->op = op;
 }