Assert that the separation of two annotations on function type during rendering it, is any whitespace-like symbol, not only whitespace itself

E.g. in quick doc mode (HTML), it may be line break

^KT-38747 Fixed

core/descriptors/src/org/jetbrains/kotlin/renderer/DescriptorRendererImpl.kt

@@ -323,7 +323,7 @@ internal class DescriptorRendererImpl(
                 insert(lengthBefore, '(')
             } else {
                 if (hasAnnotations) {
-                    assert(last() == ' ')
+                    assert(last().isWhitespace())
                     if (get(lastIndex - 1) != ')') {
                         // last annotation rendered without parenthesis - need to add them otherwise parsing will be incorrect
                         insert(lastIndex, "()")