+/* Find a label at the end of the function or before a RETURN. If there
+ is none, try to make one. If that fails, returns 0.
+
+ The property of such a label is that it is placed just before the
+ epilogue or a bare RETURN insn, so that another bare RETURN can be
+ turned into a jump to the label unconditionally. In particular, the
+ label cannot be placed before a RETURN insn with a filled delay slot.
+
+ ??? There may be a problem with the current implementation. Suppose
+ we start with a bare RETURN insn and call find_end_label. It may set
+ end_of_function_label just before the RETURN. Suppose the machinery
+ is able to fill the delay slot of the RETURN insn afterwards. Then
+ end_of_function_label is no longer valid according to the property
+ described above and find_end_label will still return it unmodified.
+ Note that this is probably mitigated by the following observation:
+ once end_of_function_label is made, it is very likely the target of
+ a jump, so filling the delay slot of the RETURN will be much more
+ difficult. */