Revert & fix "Revert ".eager shouldn't flatten" (breaks panda reboots…

…trap)"

This reverts commit 7b153f5.
.eager should actually be eager, even if it's called on a Parcel :P
More importantly, EAGER should actually eagerify its arguments. The
issue was that it was making a Parcel, passing the Parcel to Any.eager
to get flattened, and from there passed to List.eager. So we just make a flat
List instead and call List.eager.

src/core/Any.pm

@@ -57,10 +57,10 @@ my class Any { # declared in BOOTSTRAP
 
     proto method eager(|) { * }
     multi method eager(Any:U:) {
-        nqp::p6list(nqp::list(),     List, Bool::True).eager;
+        nqp::p6list(nqp::list(),     List, Mu).eager;
     }
     multi method eager(Any:D:) {
-        nqp::p6list(nqp::list(self), List, Bool::True).eager;
+        nqp::p6list(nqp::list(self), List, Mu).eager;
     }
 
     proto method hash(|) { * }

src/core/List.pm

@@ -646,7 +646,7 @@ my class List does Positional { # declared in BOOTSTRAP
 
 # internal, caps to not hide 'eager' keyword
 sub EAGER(|) {
-    nqp::p6parcel(nqp::p6argvmarray(), Any).eager
+    nqp::p6list(nqp::p6argvmarray(), List, Bool::True).eager
 }
 
 sub flat(|) {

src/core/Parcel.pm

@@ -74,6 +74,7 @@ my class Parcel does Positional { # declared in BOOTSTRAP
     method flat()  { nqp::p6list(nqp::clone($!storage), List, Bool::True) }
     method list()  { nqp::p6list(nqp::clone($!storage), List, Mu) }
     method lol()   { nqp::p6list(nqp::clone($!storage), LoL, Mu) }
+    method eager() { nqp::p6list(nqp::clone($!storage), List, Mu).eager }
 
     method reverse() {
         my Mu $reverse  := nqp::list();