Stuff that will help when protos of Any-iterable sub forms get changed to **@

noflat_in_core.diff

diff --git a/src/core/Capture.pm b/src/core/Capture.pm
index 80d013c..dacdb85 100644
--- a/src/core/Capture.pm
+++ b/src/core/Capture.pm
@@ -96,8 +96,8 @@ my class Capture { # declared in BOOTSTRAP
         if self.^name eq 'Capture' {
             "\\({
                 join ', ',
-                    (nqp::atpos($!list, $_).perl for ^nqp::elems($!list)),
-                    %hash.sort.map( *.perl )
+                    |(nqp::atpos($!list, $_).perl for ^nqp::elems($!list)),
+                    |%hash.sort.map( *.perl )
             })";
         } else {
             self.^name
diff --git a/src/core/CompUnitRepo.pm b/src/core/CompUnitRepo.pm
index 29aa4f1..78ae099 100644
--- a/src/core/CompUnitRepo.pm
+++ b/src/core/CompUnitRepo.pm
@@ -151,7 +151,7 @@ RAKUDO_MODULE_DEBUG("Parsing specs: $specs")
         if PARSE-INCLUDE-SPEC($spec, $default-short-id) -> $triplet {
             @found.push: join "#",
               $triplet[0],
-              $triplet[1].map({ .key ~ "<" ~ .value ~ ">" }),
+              |$triplet[1].map({ .key ~ "<" ~ .value ~ ">" }),
               $triplet[2];
             $default-short-id = $triplet[0];
         }
diff --git a/src/core/Exception.pm b/src/core/Exception.pm
index 18429af..448c385 100644
--- a/src/core/Exception.pm
+++ b/src/core/Exception.pm
@@ -1895,7 +1895,7 @@ my class X::Multi::Ambiguous is Exception {
     method message {
         join "\n",
             "Ambiguous call to '$.dispatcher.name()'; these signatures all match:",
-            @.ambiguous.map(*.signature.perl)
+            |@.ambiguous.map(*.signature.perl)
     }
 }

@@ -1941,7 +1941,7 @@ my class X::Multi::NoMatch is Exception {
         @priors.join ~
         join "\n    ",
             "Cannot call $.dispatcher.name()$cap; none of these signatures match:",
-            @cand;
+            |@cand;
     }
 }

diff --git a/src/core/IO/Spec/Win32.pm b/src/core/IO/Spec/Win32.pm
index 2c4550e..bed5eb1 100644
--- a/src/core/IO/Spec/Win32.pm
+++ b/src/core/IO/Spec/Win32.pm
@@ -193,7 +193,7 @@ my class IO::Spec::Win32 is IO::Spec::Unix {
             $volume ~= '\\';
         }

-        $path = join "\\", $path, @rest.flat;
+        $path = join "\\", $path, |@rest;
         $path ~~ s:g/ <$slash>+ /\\/;                              # /xx\\yy   --> \xx\yy
         $path ~~ s:g/[ ^ | '\\']   '.'  '\\.'*  [ '\\' | $ ]/\\/;  # xx/././yy --> xx/yy
         if $parent {
diff --git a/src/core/Str.pm b/src/core/Str.pm
index 905da28..3bd669d 100644
--- a/src/core/Str.pm
+++ b/src/core/Str.pm
@@ -933,7 +933,7 @@ my class Str does Stringy { # declared in BOOTSTRAP
                 $prev-pos = .to;
                 # we don't want the dummy object
                 $elems-- ?? Slip.new($value, $_) !! $value;
-            }, matches, Match.new( :from(self.chars) );
+            }, |matches, Match.new( :from(self.chars) );
             #           ^-- add dummy for last
         }
         else {
@@ -941,7 +941,7 @@ my class Str does Stringy { # declared in BOOTSTRAP
                 my $value = substr(self, $prev-pos, .from - $prev-pos);
                 $prev-pos = .to;
                 $value;
-            }, matches, Match.new( :from(self.chars) );
+            }, |matches, Match.new( :from(self.chars) );
             #           ^-- add dummy for last
         }
     }