beam_validator: Fail when trying to set the type of a dead value

The comment is outdated; trying to update the type of a dead value
will result in a type conflict, making this code unreachable.

1 files changed, 3 insertions, 10 deletions

diff --git a/lib/compiler/src/beam_validator.erl b/lib/compiler/src/beam_validator.erl
index 79bd6480a4..5d017a0568 100644
--- a/lib/compiler/src/beam_validator.erl
+++ b/lib/compiler/src/beam_validator.erl
@@ -1848,16 +1848,9 @@ get_reg_vref({y,_}=Src, #vst{current=#st{ys=Ys}}) ->
     end.
 
 set_type(Type, #value_ref{}=Ref, #vst{current=#st{vs=Vs0}=St}=Vst) ->
-    case Vs0 of
-        #{ Ref := #value{}=Entry } ->
-            Vs = Vs0#{ Ref => Entry#value{type=Type} },
-            Vst#vst{current=St#st{vs=Vs}};
-        #{} ->
-            %% Dead references may happen during type inference and are not an
-            %% error in and of themselves. If a problem were to arise from this
-            %% it'll explode elsewhere.
-            Vst
-    end.
+    #{ Ref := #value{}=Entry } = Vs0,
+    Vs = Vs0#{ Ref => Entry#value{type=Type} },
+    Vst#vst{current=St#st{vs=Vs}}.
 
 new_value(Type, Op, Ss, #vst{current=#st{vs=Vs0}=St,ref_ctr=Counter}=Vst) ->
     Ref = #value_ref{id=Counter},