There is some behavior change regarding the new WrapWithSafeLetCall quickfix
1. it now works correctly on binary expressions by wrapping it with `()`
2. it now looks for a nullable position upward and do the modification there,
if possible. For example, consider the following code
```
fun bar(s: String): String = s
fun test(s: String?) {
bar(bar(bar(<caret>s)))
}
```
After applying this fix, FE1.0 yields
```
bar(bar(s?.let { bar(it) }))
```
while the new implementation yields
```
s?.let { bar(bar(bar(it))) }
```
This behavior aligns with FE1.0 if `bar` accepts nullable values.
Tianyu Geng
e1b542314a