Don't generate full protopads unless needed

In subs with no unclonable phasers or methods, it's not necessary to have a
protopad.  This is the first step and elides most variables from such unneeded
pads.  -60K testsuite

Body.pm

@@ -70,6 +70,23 @@ use CgOp ();
         $self->scopetree(\%h);
     }
 
+    # call after decl lifting
+    has needs_protopad => (isa => 'Bool', is => 'ro', lazy_build => 1);
+    sub _build_needs_protopad {
+        my ($self) = @_;
+
+        for my $d (@{ $self->decls }) {
+            return 1 if $d->needs_protopad;
+            for my $b ($d->bodies) {
+                return 1 if $b->needs_protopad;
+            }
+        }
+
+        return 0;
+    }
+
+    sub needs_protovars { $_[0]->needs_protopad || $_[0]->mainline }
+
     sub lift_decls {
         my ($self) = @_;
         my (@self_q, @outer_q);

Decl.pm

@@ -13,6 +13,7 @@ use CgOp;
     sub used_slots   { () }
     sub preinit_code { CgOp::noop }
     sub enter_code   { CgOp::noop }
+    sub needs_protopad {0}
 
     sub outer_decls  {}
     sub bodies       {}
@@ -36,6 +37,7 @@ use CgOp;
         $self->has_var ? [$self->var, 'Variable', 1] : ();
     }
 
+    sub needs_protopad { 1 }
     sub preinit_code {
         my ($self, $body) = @_;
         my $c = CgOp::prog(CgOp::protosub($self->code),
@@ -64,9 +66,11 @@ use CgOp;
     sub preinit_code {
         my ($self, $body) = @_;
 
-        CgOp::prog(
-            CgOp::protosub($self->code),
-            CgOp::proto_var($self->var, CgOp::sub_var($self->code)));
+        $body->needs_protovars ?
+            CgOp::prog(
+                CgOp::protosub($self->code),
+                CgOp::proto_var($self->var, CgOp::sub_var($self->code))) :
+            CgOp::protosub($self->code);
     }
 
     sub enter_code {
@@ -99,6 +103,8 @@ use CgOp;
     sub preinit_code {
         my ($self, $body) = @_;
 
+        return CgOp::noop if !$body->needs_protovars;
+
         if ($self->list) {
             CgOp::proto_var($self->slot, CgOp::newblanklist);
         } elsif ($self->hash) {
@@ -192,7 +198,7 @@ use CgOp;
 
     sub preinit_code {
         my ($self, $body) = @_;
-        $self->slot ?
+        ($self->slot && $body->needs_protovars) ?
             CgOp::proto_var($self->slot, CgOp::scopedlex($self->backing)) :
             CgOp::noop;
     }
@@ -215,6 +221,7 @@ use CgOp;
 
     has unitname => (isa => 'Str', is => 'ro', required => 1);
 
+    sub needs_protopad { 1 }
     sub preinit_code {
         my ($self, $body) = @_;
 
@@ -259,6 +266,7 @@ use CgOp;
     sub make_how { CgOp::newscalar(CgOp::null('IP6')); }
     sub finish_obj { CgOp::noop; }
 
+    sub needs_protopad { 1 }
     sub preinit_code {
         my ($self, $body) = @_;
 
@@ -352,6 +360,7 @@ use CgOp;
     has name => (is => 'ro', isa => 'Str', required => 1);
     has var  => (is => 'ro', isa => 'Str', required => 1);
 
+    sub needs_protopad { 1 }
     sub preinit_code {
         my ($self, $body) = @_;
         if ($body->type !~ /class|grammar|role/) {
@@ -375,6 +384,7 @@ use CgOp;
     has name => (is => 'ro', isa => 'Str', required => 1);
     has var  => (is => 'ro', isa => 'Str', required => 1);
 
+    sub needs_protopad { 1 }
     sub preinit_code {
         my ($self, $body) = @_;
         CgOp::sink(
@@ -393,6 +403,7 @@ use CgOp;
 
     has name => (is => 'ro', isa => 'Str', required => 1);
 
+    sub needs_protopad { 1 }
     sub preinit_code {
         my ($self, $body) = @_;
         if ($body->type ne 'class' && $body->type ne 'grammar' &&
@@ -417,6 +428,7 @@ use CgOp;
 
     has name => (is => 'ro', isa => 'Str', required => 1);
 
+    sub needs_protopad { 1 }
     sub preinit_code {
         my ($self, $body) = @_;
         if ($body->type ne 'class' && $body->type ne 'grammar' &&