K2: Support callable references adaptation on top-level

^KT-45989 In progress
^KT-54709 Related
^KT-55217 Fixed

compiler/testData/diagnostics/tests/callableReference/adapted/simpleAdaptationOutsideOfCall.fir.kt

@@ -0,0 +1,10 @@
+// SKIP_TXT
+fun baz(options: String = ""): String = ""
+
+fun runForString(x: () -> String) {}
+
+fun foo(dumpStrategy: String) {
+    val dump0: () -> String = ::baz
+
+    runForString(::baz)
+}

compiler/testData/diagnostics/tests/callableReference/adapted/simpleAdaptationOutsideOfCall.kt

@@ -0,0 +1,10 @@
+// SKIP_TXT
+fun baz(options: String = ""): String = ""
+
+fun runForString(x: () -> String) {}
+
+fun foo(dumpStrategy: String) {
+    val dump0: () -> String = <!TYPE_MISMATCH!>::<!TYPE_MISMATCH!>baz<!><!>
+
+    runForString(::baz)
+}

compiler/testData/diagnostics/tests/callableReference/function/ambiguityTopLevelVsTopLevel.fir.kt

@@ -5,5 +5,5 @@ fun foo(x: Any, y: Int) = y
 fun main() {
     ::<!OVERLOAD_RESOLUTION_AMBIGUITY!>foo<!>
 
-    val fooRef: (Int, Any) -> Unit = ::<!UNRESOLVED_REFERENCE!>foo<!>
+    val fooRef: (Int, Any) -> Unit = ::foo
 }

compiler/testData/diagnostics/tests/callableReference/resolve/withVararg.fir.kt

@@ -6,5 +6,5 @@ fun foo(i: Int) {}
 
 val fn1: (Int) -> Unit = ::foo
 val fn2: (IntArray) -> Unit = ::foo
-val fn3: (Int, Int) -> Unit = ::<!UNRESOLVED_REFERENCE!>foo<!>
+val fn3: (Int, Int) -> Unit = ::foo
 val fn4: (Array<String>) -> Unit = ::foo

compiler/testData/diagnostics/tests/inference/callableReferences/conversionLastStatementInLambda.fir.kt

@@ -4,8 +4,7 @@
 fun main(b: Boolean) {
     callWithLambda {
         // The only relevant case for KT-55729, Unit conversion should work, but doesn't in K1 1.8.0
-        // For K2, it still doesn't work (see KT-55936)
-        ::<!UNRESOLVED_REFERENCE!>test1<!>
+        ::test1
     }
 
     callWithLambda {
@@ -23,8 +22,8 @@ fun main(b: Boolean) {
     }
 
     callWithLambda {
-        // That hasn't been working ever in K1 nor K2
-        (::<!UNRESOLVED_REFERENCE!>test1<!>)
+        // Doesn't work in K1, but does in K2
+        (::test1)
     }
 }
 

compiler/testData/diagnostics/tests/inference/callableReferences/conversionLastStatementInLambda.kt

@@ -4,7 +4,6 @@
 fun main(b: Boolean) {
     callWithLambda {
         // The only relevant case for KT-55729, Unit conversion should work, but doesn't in K1 1.8.0
-        // For K2, it still doesn't work (see KT-55936)
         ::test1
     }
 
@@ -23,7 +22,7 @@ fun main(b: Boolean) {
     }
 
     callWithLambda {
-        // That hasn't been working ever in K1 nor K2
+        // Doesn't work in K1, but does in K2
         (<!TYPE_MISMATCH, TYPE_MISMATCH!>::<!TYPE_MISMATCH!>test1<!><!>)
     }
 }