Change the first argument of Perl_fetch_cop_label() to COP *

From a suggestion from Ben Morrow.

The first argument used to be struct refcounted_he *, which exposed an
implementation detail - that the COP's labels are (now) stored in this way.

Google Code Search and an unpacked CPAN both fail to find any users of this
API, so the impact should be minimal.

1 files changed, 5 insertions, 2 deletions

diff --git a/hv.c b/hv.c
index d8ba456745..567b4d973d 100644
--- a/hv.c
+++ b/hv.c
@@ -2940,8 +2940,11 @@ Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
 /* pp_entereval is aware that labels are stored with a key ':' at the top of
    the linked list.  */
 const char *
-Perl_fetch_cop_label(pTHX_ struct refcounted_he *const chain, STRLEN *len,
-		     U32 *flags) {
+Perl_fetch_cop_label(pTHX_ COP *cop, STRLEN *len, U32 *flags) {
+    struct refcounted_he *const chain = cop->cop_hints_hash;
+
+    PERL_ARGS_ASSERT_FETCH_COP_LABEL;
+
     if (!chain)
 	return NULL;
 #ifdef USE_ITHREADS