[FIR] Try to infer result type of incomplete when expression

^KT-62069 Fixed

compiler/testData/diagnostics/tests/controlStructures/ifWhenWithoutElse.fir.kt

@@ -11,18 +11,18 @@ val mlist = MList()
 fun work() {}
 
 val xx1 = <!INVALID_IF_AS_EXPRESSION!>if<!> (true) 42
-val xx2: Unit = <!INVALID_IF_AS_EXPRESSION!>if<!> (true) 42
+val xx2: Unit = <!INITIALIZER_TYPE_MISMATCH!><!INVALID_IF_AS_EXPRESSION!>if<!> (true) 42<!>
 val xx3 = idAny(<!INVALID_IF_AS_EXPRESSION!>if<!> (true) 42)
 val xx4 = id(<!INVALID_IF_AS_EXPRESSION!>if<!> (true) 42)
-val xx5 = idUnit(<!INVALID_IF_AS_EXPRESSION!>if<!> (true) 42)
+val xx5 = idUnit(<!ARGUMENT_TYPE_MISMATCH!><!INVALID_IF_AS_EXPRESSION!>if<!> (true) 42<!>)
 val xx6 = null ?: <!INVALID_IF_AS_EXPRESSION!>if<!> (true) 42
 val xx7 = "" + <!INVALID_IF_AS_EXPRESSION!>if<!> (true) 42
 
 val wxx1 = <!NO_ELSE_IN_WHEN!>when<!> { true -> 42 }
-val wxx2: Unit = <!NO_ELSE_IN_WHEN!>when<!> { true -> 42 }
+val wxx2: Unit = <!INITIALIZER_TYPE_MISMATCH!><!NO_ELSE_IN_WHEN!>when<!> { true -> 42 }<!>
 val wxx3 = idAny(<!NO_ELSE_IN_WHEN!>when<!> { true -> 42 })
 val wxx4 = id(<!NO_ELSE_IN_WHEN!>when<!> { true -> 42 })
-val wxx5 = idUnit(<!NO_ELSE_IN_WHEN!>when<!> { true -> 42 })
+val wxx5 = idUnit(<!ARGUMENT_TYPE_MISMATCH!><!NO_ELSE_IN_WHEN!>when<!> { true -> 42 }<!>)
 val wxx6 = null ?: <!NO_ELSE_IN_WHEN!>when<!> { true -> 42 }
 val wxx7 = "" + <!NO_ELSE_IN_WHEN!>when<!> { true -> 42 }
 
@@ -57,7 +57,7 @@ fun foo1(x: String?) {
     "" + <!INVALID_IF_AS_EXPRESSION!>if<!> (true) 42
     w@while (true) {
         x ?: <!INVALID_IF_AS_EXPRESSION!>if<!> (true) break
-        x ?: <!NO_ELSE_IN_WHEN!>when<!> { true -> break@w }
+        x <!USELESS_ELVIS!>?: <!NO_ELSE_IN_WHEN!>when<!> { true -> break@w }<!>
     }
 }
 

compiler/testData/diagnostics/tests/controlStructures/noTypeMismatchWithWhenWithoutElse.fir.kt

@@ -0,0 +1,11 @@
+// ISSUE: KT-62069
+
+enum class ExhaustiveEnum { ONE, TWO }
+
+fun exhaust(ee: ExhaustiveEnum) {
+    var v = 0
+    v = <!NO_ELSE_IN_WHEN!>when<!> (ee) {
+        ExhaustiveEnum.ONE -> 1
+    }
+    v = <!INVALID_IF_AS_EXPRESSION!>if<!> (ee == ExhaustiveEnum.ONE) 2
+}

compiler/testData/diagnostics/tests/controlStructures/noTypeMismatchWithWhenWithoutElse.kt

@@ -0,0 +1,11 @@
+// ISSUE: KT-62069
+
+enum class ExhaustiveEnum { ONE, TWO }
+
+fun exhaust(ee: ExhaustiveEnum) {
+    var <!ASSIGNED_BUT_NEVER_ACCESSED_VARIABLE!>v<!> = 0
+    v = <!NO_ELSE_IN_WHEN!>when<!> (ee) {
+        ExhaustiveEnum.ONE -> 1
+    }
+    v = <!TYPE_MISMATCH!><!INVALID_IF_AS_EXPRESSION!>if<!> (ee == ExhaustiveEnum.ONE) 2<!>
+}