delete unnecessary branch

At last, not only myself but also your compiler are fully confident
that the method entries pointed from call caches are immutable.  We
don't have to worry about silent updates.  Just delete the branch
that is now always false.

Calculating -------------------------------------
                           ours       trunk
vm2_poly_same_method     2.142M      2.070M i/s -      6.000M times in 2.801148s 2.898994s

Comparison:
             vm2_poly_same_method
                ours:   2141979.2 i/s
               trunk:   2069683.8 i/s - 1.03x  slower

1 files changed, 1 insertions, 1 deletions

diff --git a/insns.def b/insns.def
index f365106e2c..e3edc5e29f 100644
--- a/insns.def
+++ b/insns.def
@@ -911,7 +911,7 @@ invokeblock
 // attr rb_snum_t sp_inc = sp_inc_of_invokeblock(ci);
 {
     static struct rb_call_cache cc = {
-        0, 0, NULL, NULL, vm_invokeblock_i,
+        0, 0, NULL, vm_invokeblock_i,
     };
 
     VALUE bh = VM_BLOCK_HANDLER_NONE;