[FIR] Generate dispatch & extension receivers for variable assignments

compiler/fir/analysis-tests/testData/resolve/propertyFromJavaPlusAssign.txt

@@ -1,4 +1,4 @@
 FILE: main.kt
     public final fun test(b: R|B|): R|kotlin/Unit| {
-        R|/B.text| = R|<local>/b|.R|/B.text|.R|kotlin/String.plus|(String())
+        R|<local>/b|.R|/B.text| = R|<local>/b|.R|/B.text|.R|kotlin/String.plus|(String())
     }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/body/resolve/FirExpressionsResolveTransformer.kt

@@ -290,6 +290,10 @@ class FirExpressionsResolveTransformer(transformer: FirBodyResolveTransformer) :
                                     source = operatorCall.argument.source
                                     diagnostic = ConeVariableExpectedError()
                                 }
+                            (leftArgument as? FirQualifiedAccess)?.let {
+                                dispatchReceiver = it.dispatchReceiver
+                                extensionReceiver = it.extensionReceiver
+                            }
                         }
                     assignment.transform(transformer, ResolutionMode.ContextIndependent)
                 }