Distinguishable yada exceptions

Compile-time error

Stage parse      : Could not locate compile-time value for symbol X::Stub::Executed
   at src/Perl6/World.nqp:2657  (blib/Perl6/World.moarvm:find_symbol:260)
 from src/gen/m-Perl6-Actions.nqp:4208  (blib/Perl6/Actions.moarvm:make_yada:81)

distinguishable-yada-exceptions.patch

diff --git a/src/Perl6/Actions.nqp b/src/Perl6/Actions.nqp
index c472c56..4011acd 100644
--- a/src/Perl6/Actions.nqp
+++ b/src/Perl6/Actions.nqp
@@ -4206,7 +4206,8 @@ class Perl6::Actions is HLL::Actions does STDActions {
         $past.name($name);
         $past.node($/);
         unless +$past.list() {
-            $past.push($*W.add_string_constant('Stub code executed'));
+            $past.push(QAST::Op.new(:op<callmethod>, :name<new>,
+                       QAST::WVal.new( :value($*W.find_symbol(['X::Stub::Executed'])) )));
         }
         $past
     }
diff --git a/src/core/Exception.pm b/src/core/Exception.pm
index 619e34f..e204b87 100644
--- a/src/core/Exception.pm
+++ b/src/core/Exception.pm
@@ -1203,6 +1203,10 @@ my class X::Package::Stubbed does X::Comp {
     }
 }
 
+my class X::Stub::Executed is Exception {
+    method message { 'Stub code executed' }
+}
+
 my class X::Phaser::PrePost is Exception {
     has $.phaser = 'PRE';
     has $.condition;