Bug 1660409 - Part 4: Transpile ArrayJoin. r=jandem

Differential Revision: https://phabricator.services.mozilla.com/D88565

js/src/jit/CacheIROps.yaml

@@ -901,7 +901,7 @@
 
 - name: ArrayJoinResult
   shared: false
-  transpile: false
+  transpile: true
   cost_estimate: 5
   args:
     obj: ObjId

js/src/jit/WarpCacheIRTranspiler.cpp

@@ -2342,6 +2342,21 @@ bool WarpCacheIRTranspiler::emitArrayPush(ObjOperandId objId,
   return resumeAfter(ins);
 }
 
+bool WarpCacheIRTranspiler::emitArrayJoinResult(ObjOperandId objId,
+                                                StringOperandId sepId) {
+  MDefinition* obj = getOperand(objId);
+  MDefinition* sep = getOperand(sepId);
+
+  // TODO(Warp): This flag only make sense for the Ion implementation. Remove it
+  // when IonBuilder is gone.
+  bool optimizeForArray = true;
+  auto* join = MArrayJoin::New(alloc(), obj, sep, optimizeForArray);
+  addEffectful(join);
+
+  pushResult(join);
+  return resumeAfter(join);
+}
+
 bool WarpCacheIRTranspiler::emitPackedArrayPopResult(ObjOperandId arrayId) {
   MDefinition* array = getOperand(arrayId);