Safe call arguments are now handled as nullable in generic resolver #KT-9985 Fixed

compiler/testData/diagnostics/testsWithStdLib/kt9985.kt

@@ -0,0 +1,3 @@
+fun foo(l: List<String>?) {
+  Pair(l?.joinToString(), "")
+}

compiler/testData/diagnostics/testsWithStdLib/kt9985.txt

@@ -0,0 +1,3 @@
+package
+
+public fun foo(/*0*/ l: kotlin.collections.List<kotlin.String>?): kotlin.Unit