IR: remove unneeded casts after making IrCall's symbol a simple function

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/PrimitiveCompanionLowering.kt

@@ -6,7 +6,6 @@
 package org.jetbrains.kotlin.ir.backend.js.lower
 
 import org.jetbrains.kotlin.backend.common.BodyLoweringPass
-import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.ir.backend.js.JsIrBackendContext
 import org.jetbrains.kotlin.ir.declarations.IrClass
 import org.jetbrains.kotlin.ir.declarations.IrDeclaration
@@ -73,9 +72,7 @@ class PrimitiveCompanionLowering(val context: JsIrBackendContext) : BodyLowering
             override fun visitCall(expression: IrCall): IrExpression {
                 val newCall = super.visitCall(expression) as IrCall
 
-                val function = expression.symbol.owner as IrSimpleFunction
-
-                val actualFunction = getActualPrimitiveCompanionPropertyAccessor(function)
+                val actualFunction = getActualPrimitiveCompanionPropertyAccessor(expression.symbol.owner)
                     ?: return newCall
 
                 return irCall(newCall, actualFunction)

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/calls/PrimitiveContainerMemberCallTransformer.kt

@@ -59,13 +59,12 @@ class PrimitiveContainerMemberCallTransformer(private val context: JsIrBackendCo
         }
     }
 
-    override fun transformFunctionAccess(expression: IrFunctionAccessExpression): IrExpression {
-        val symbol = expression.symbol
-        symbolToTransformer[symbol]?.let {
-            return it(expression)
+    override fun transformFunctionAccess(call: IrFunctionAccessExpression): IrExpression {
+        symbolToTransformer[call.symbol]?.let {
+            return it(call)
         }
 
-        return expression
+        return call
     }
 }
 

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/jsAstUtils.kt

@@ -78,11 +78,8 @@ fun translateCall(
     transformer: IrElementToJsExpressionTransformer
 ): JsExpression {
     val function = expression.symbol.owner.realOverrideTarget
-    require(function is IrSimpleFunction) { "Only IrSimpleFunction could be called via IrCall" } // TODO: fix it in IrCall
 
-    val symbol = function.symbol
-
-    context.staticContext.intrinsics[symbol]?.let {
+    context.staticContext.intrinsics[function.symbol]?.let {
         return it(expression, context)
     }