JVM IR: substitute generic type for inline class replacement function calls

The main change here is in `JvmInlineClassLowering.visitFunctionAccess`,
where we now store the substituted return type of the function as the
type of the call expression. Without it, the call could have a
meaningless type, e.g. some `T` which is inaccessible at that place, and
that could backfire in subsequent lowerings in codegen. For example, in
the `stringPlus.kt` test, it would prevent the code in
`FlattenStringConcatenationLowering.isStringPlusCall` from recognizing
and replacing the `String.plus` call, leading to a codegen exception.

Other changes are mostly cosmetics to make the code similar to
`visitFunctionReference`, and preventive optimizations for the case when
the substitution map is empty.

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/IrUtils.kt

@@ -16,7 +16,10 @@ import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrConstructorCallImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrTypeOperatorCallImpl
 import org.jetbrains.kotlin.ir.symbols.*
-import org.jetbrains.kotlin.ir.types.*
+import org.jetbrains.kotlin.ir.types.IrSimpleType
+import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.types.isAny
+import org.jetbrains.kotlin.ir.types.isSubtypeOf
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.SpecialNames
 import org.jetbrains.kotlin.utils.DFS
@@ -512,10 +515,12 @@ val IrFunction.allTypeParameters: List<IrTypeParameter>
     else
         typeParameters
 
-fun IrMemberAccessExpression<*>.getTypeSubstitutionMap(irFunction: IrFunction): Map<IrTypeParameterSymbol, IrType> =
-    irFunction.allTypeParameters.withIndex().associate {
+fun IrMemberAccessExpression<*>.getTypeSubstitutionMap(irFunction: IrFunction): Map<IrTypeParameterSymbol, IrType> {
+    val typeParameters = irFunction.allTypeParameters
+    return if (typeParameters.isEmpty()) emptyMap() else typeParameters.withIndex().associate {
         it.value.symbol to getTypeArgument(it.index)!!
     }
+}
 
 val IrFunctionReference.typeSubstitutionMap: Map<IrTypeParameterSymbol, IrType>
     get() = getTypeSubstitutionMap(symbol.owner)
@@ -536,4 +541,4 @@ val IrFunction.originalFunction: IrFunction
     get() = (this as? IrAttributeContainer)?.attributeOwnerId as? IrFunction ?: this
 
 val IrProperty.originalProperty: IrProperty
-    get() = attributeOwnerId as? IrProperty ?: this
+    get() = attributeOwnerId as? IrProperty ?: this