&CORE::foo() for (sys)read and recv

These are grouped together because they all have \$ in their
prototypes.

This commit allows the subs in the CORE package under those names to
be called through references and via &ampersand syntax.

The coreargs op in the subroutine is marked with the OPpSCALARMOD
flag.  (scalar_mod_type in op.c returns true for these three ops,
indicating that the OA_SCALARREF parameter is \$, not \[$@%(&)*].)

pp_coreargs uses that flag to decide what arguments to reject.

1 files changed, 2 insertions, 0 deletions

diff --git a/op.c b/op.c
index 4f42daa1da..73dccf8f17 100644
--- a/op.c
+++ b/op.c
@@ -10382,6 +10382,8 @@ Perl_coresub_op(pTHX_ SV * const coreargssv, const int code,
 	    o = convert(opnum,0,argop);
 	    if (is_handle_constructor(o, 2))
 		argop->op_private |= OPpCOREARGS_DEREF2;
+	    if (scalar_mod_type(NULL, opnum))
+		argop->op_private |= OPpCOREARGS_SCALARMOD;
 	    goto onearg;
 	}
     }