Revert "FIR checkers: report SMARTCAST_IMPOSSIBLE"

This reverts commit 84334b08

compiler/testData/diagnostics/tests/smartCasts/publicVals/customGetter.fir.kt

@@ -0,0 +1,13 @@
+public class X {
+    private val x : String? = null
+    public val y: CharSequence?
+        get() = x?.subSequence(0, 1)
+    public fun fn(): Int {
+        if (y != null)
+            // With non-default getter smartcast is not possible
+            return y<!UNSAFE_CALL!>.<!>length
+        else
+            return 0
+    }
+}
+

compiler/testData/diagnostics/tests/smartCasts/publicVals/customGetter.kt

@@ -1,4 +1,3 @@
-// FIR_IDENTICAL
 public class X {
     private val x : String? = null
     public val y: CharSequence?

compiler/testData/diagnostics/tests/smartCasts/publicVals/open.fir.kt

@@ -0,0 +1,11 @@
+public open class A() {
+    public open val foo: Int? = 1
+}
+
+infix fun Int.bar(i: Int) = i
+
+fun test() {
+    val p = A()
+    // For open value properties, smart casts should not work
+    if (p.foo is Int) p.foo <!UNSAFE_INFIX_CALL!>bar<!> 11
+}

compiler/testData/diagnostics/tests/smartCasts/publicVals/open.kt

@@ -1,4 +1,3 @@
-// FIR_IDENTICAL
 public open class A() {
     public open val foo: Int? = 1
 }

compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModule.fir.kt

@@ -0,0 +1,35 @@
+// MODULE: m1
+// FILE: a.kt
+
+package a
+
+public class X {
+    public val x : String? = null
+}
+
+// MODULE: m2(m1)
+// FILE: b.kt
+
+package b
+
+import a.X
+
+public fun X.gav(): Int {
+    if (x != null)
+        // Smart cast is not possible if definition is in another module
+        return x<!UNSAFE_CALL!>.<!>length
+    else
+        return 0
+}
+
+// FILE: c.kt
+
+package a
+
+public fun X.gav(): Int {
+    if (x != null)
+        // Even if it's in the same package
+        return x<!UNSAFE_CALL!>.<!>length
+    else
+        return 0
+}

compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModule.kt

@@ -1,4 +1,3 @@
-// FIR_IDENTICAL
 // MODULE: m1
 // FILE: a.kt
 

compiler/testData/diagnostics/tests/smartCasts/publicVals/var.fir.kt

@@ -0,0 +1,15 @@
+public class X {
+    public var x : String? = null
+    private var y: String? = "abc"
+    public fun fn(): Int {
+        if (x != null)
+            // Smartcast is not possible for variable properties
+            return x<!UNSAFE_CALL!>.<!>length
+        else if (y != null)
+            // Even if they are private
+            return y<!UNSAFE_CALL!>.<!>length
+        else
+            return 0
+    }
+}
+

compiler/testData/diagnostics/tests/smartCasts/publicVals/var.kt

@@ -1,4 +1,3 @@
-// FIR_IDENTICAL
 public class X {
     public var x : String? = null
     private var y: String? = "abc"