Fix typo in op.h

This caused all OP structures to be larger than intended; for example, it
made `struct op` 48 bytes rather than 40 on Mac OS X x86-64.

1 files changed, 1 insertions, 1 deletions

diff --git a/op.h b/op.h
index 3b8eb17acb..9f94caf875 100644
--- a/op.h
+++ b/op.h
@@ -52,7 +52,7 @@ typedef PERL_BITFIELD16 Optype;
     PERL_BITFIELD16 op_savefree:1;	\
     PERL_BITFIELD16 op_static:1;	\
     PERL_BITFIELD16 op_folded:1;	\
-    PERL_BITFIELD16 op_lastsib;		\
+    PERL_BITFIELD16 op_lastsib:1;       \
     PERL_BITFIELD16 op_spare:1;		\
     U8		op_flags;		\
     U8		op_private;