Fix small memory leak in new join feature - see 5ab9168

Author: lovell

src/pipeline.cc

@@ -1369,6 +1369,9 @@ class PipelineWorker : public Napi::AsyncWorker {
     for (sharp::InputDescriptor *input : baton->joinChannelIn) {
       delete input;
     }
+    for (sharp::InputDescriptor *input : baton->join) {
+      delete input;
+    }
     delete baton;
 
     // Decrement processing task counter

test/leak/sharp.supp

@@ -936,6 +936,24 @@
   ...
   fun:_ZN2v88internal18ArrayBufferSweeper10ReleaseAllEv
 }
+{
+  cond_v8_ZN2v88internal8compiler12PipelineImpl13OptimizeGraphEPNS1_7LinkageE
+  Memcheck:Cond
+  ...
+  fun:_ZN2v88internal8compiler12PipelineImpl13OptimizeGraphEPNS1_7LinkageE
+}
+{
+  cond_v8_ZN2v88internal4Heap20HasLowAllocationRateEv
+  Memcheck:Cond
+  ...
+  fun:_ZN2v88internal4Heap20HasLowAllocationRateEv
+}
+{
+  cond_v8_ZN2v88internal4Heap15RecomputeLimitsENS0_16GarbageCollectorENS_4base9TimeTicksE
+  Memcheck:Cond
+  ...
+  fun:_ZN2v88internal4Heap15RecomputeLimitsENS0_16GarbageCollectorENS_4base9TimeTicksE
+}
 {
   cond_node_Builtins_JSEntry
   Memcheck:Cond