Eliminate A Few Scalar Allocs For Push-All

I could not measure a performance benefit
in the benchmark I had, but the bytecode
got a bit simpler and total allocation count
decreased a little.

src/core/Iterator.pm6

@@ -52,10 +52,10 @@ my role Iterator {
 
     # Has the iterator produce all of its values into the target.  Typically
     # called in .STORE if the iterator is non-lazy.  Returns IterationEnd.
-    method push-all($target --> IterationEnd) {
+    method push-all(\target --> IterationEnd) {
         nqp::until( # we may not .sink $pulled here, since it can be a Seq
-          nqp::eqaddr((my $pulled := self.pull-one),IterationEnd),
-          $target.push($pulled)
+          nqp::eqaddr((my \pulled := self.pull-one),IterationEnd),
+          target.push(pulled)
         )
     }
 
@@ -66,10 +66,10 @@ my role Iterator {
     # calls push-all. If all values the iterator can produce are pushed, then
     # IterationEnd should be returned. Otherwise, return something else (Mu
     # will do fine).
-    method push-until-lazy($target) {
+    method push-until-lazy(\target) {
         nqp::unless(
           self.is-lazy,
-          self.push-all($target)
+          self.push-all(target)
         )
     }
 

src/core/List.pm6

@@ -630,14 +630,14 @@ my class List does Iterable does Positional { # declared in BOOTSTRAP
             IterationEnd
         }
 
-        method push-until-lazy($target) {
+        method push-until-lazy(\target) {
             nqp::if(
               nqp::isconcrete($!todo),
               nqp::stmts(                # something to reify still
                 (my int $elems = $!todo.reify-until-lazy),
                 nqp::while(  # doesn't sink
                   nqp::islt_i($!i = nqp::add_i($!i,1),$elems),
-                  $target.push(nqp::atpos($!reified,$!i))
+                  target.push(nqp::atpos($!reified,$!i))
                 ),
                 nqp::if(
                   $!todo.fully-reified,
@@ -652,7 +652,7 @@ my class List does Iterable does Positional { # declared in BOOTSTRAP
                 ($elems = nqp::elems($!reified)),
                 nqp::while(  # doesn't sink
                   nqp::islt_i($!i = nqp::add_i($!i,1),$elems),
-                  $target.push(nqp::atpos($!reified,$!i))
+                  target.push(nqp::atpos($!reified,$!i))
                 ),
                 IterationEnd
               )