Revert "[FIR] Enable ForbidInferringTypeVariablesIntoEmptyIntersection in 2.0"

^KT-66196 Fixed
Keep it a warning in 2.0

This reverts commit be232d3e6f.

compiler/testData/diagnostics/tests/inference/builderInference/stubTypes/intersect.fir.kt

@@ -31,7 +31,7 @@ fun <E> intersect(vararg x: In<E>): E = null as E
 fun test() {
     val ret = build {
         emit("1")
-        <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_ERROR!>intersect<!>(getIn(), getIn())
+        <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>intersect<!>(getIn(), getIn())
         intersect(getIn(), Test.foo(getIn()))
         intersect(Test.foo(getIn()), Test.foo(getIn()))
         intersect(Test.foo(getIn()), getIn())

compiler/testData/diagnostics/tests/inference/coercionToUnit/afterBareReturn.fir.kt

@@ -29,7 +29,7 @@ fun test3() = run {
 
 fun test4() = run {
     if (p) return@run
-    <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_ERROR!>incompatibleC<!>() // ? either uninferred T or error (Unit </: C)
+    <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>incompatibleC<!>() // ? either uninferred T or error (Unit </: C)
 }
 
 fun main() {

compiler/testData/diagnostics/tests/inference/coercionToUnit/coercionToUnitWithNothingType.fir.kt

@@ -47,7 +47,7 @@ fun test(i: Inv<Nothing>, iUnit: Inv<Unit>) {
 
     if (iUnit is String) {
         launch {
-            run(A.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_ERROR!>flexible<!>(iUnit)) { 42 }
+            run(A.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>flexible<!>(iUnit)) { 42 }
         }
     }
 }

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/emptyIntersectionOnIf.fir.kt

@@ -4,5 +4,5 @@ open class A
 abstract class B {
     fun test(current: A): A? =
         // K2 reports empty intersection here due to the smart cast from A to B, where A & B aren't compatible
-        <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_ERROR("K; B?, A?; multiple incompatible classes; : B, A")!>if (current === this) current else null<!>
+        <!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING("K; B?, A?; multiple incompatible classes; : B, A")!>if (current === this) current else null<!>
 }

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461.diag.txt

@@ -1,4 +1,4 @@
-/kt45461.kt:12:19: warning: type argument for a type parameter S can't be inferred because it has incompatible upper bounds: String, Int (multiple incompatible classes). This will become an error in Kotlin 2.0
+/kt45461.kt:12:19: warning: type argument for a type parameter S can't be inferred because it has incompatible upper bounds: String, Int (multiple incompatible classes). This will become an error in a future release
     Bar<String>().takeFoo(foo) // error in 1.3.72, no error in 1.4.31
                   ^^^^^^^
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461.fir.diag.txt

@@ -1 +1 @@
-/kt45461.kt:(245,252): warning: Type argument for type parameter 'S' cannot be inferred because it has incompatible upper bounds: kotlin.String, kotlin.Int (multiple incompatible classes). This will become an error in Kotlin 2.0.
+/kt45461.kt:(245,252): warning: Type argument for type parameter 'S' cannot be inferred because it has incompatible upper bounds: kotlin.String, kotlin.Int (multiple incompatible classes). This will become an error in a future release.

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_12.diag.txt

@@ -1,4 +1,4 @@
-/kt45461_12.kt:14:19: warning: type argument for a type parameter S can't be inferred because it has incompatible upper bounds: String, K (multiple incompatible classes: String, Number). This will become an error in Kotlin 2.0
+/kt45461_12.kt:14:19: warning: type argument for a type parameter S can't be inferred because it has incompatible upper bounds: String, K (multiple incompatible classes: String, Number). This will become an error in a future release
     Bar<String>().takeFoo(foo) // error in 1.3.72, no error in 1.4.31
                   ^^^^^^^
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_12.fir.diag.txt

@@ -1 +1 @@
-/kt45461_12.kt:(296,303): warning: Type argument for type parameter 'S' cannot be inferred because it has incompatible upper bounds: kotlin.String, K (multiple incompatible classes: kotlin/String, kotlin/Number). This will become an error in Kotlin 2.0.
+/kt45461_12.kt:(296,303): warning: Type argument for type parameter 'S' cannot be inferred because it has incompatible upper bounds: kotlin.String, K (multiple incompatible classes: kotlin/String, kotlin/Number). This will become an error in a future release.

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_2.diag.txt

@@ -1,7 +1,7 @@
 /kt45461_2.kt:10:10: warning: 'Int' is a final type, and thus a value of the type parameter is predetermined
 fun <K : Int> main() {
          ^^^
-/kt45461_2.kt:12:19: warning: type argument for a type parameter S can't be inferred because it has incompatible upper bounds: String, K (multiple incompatible classes: String, Int). This will become an error in Kotlin 2.0
+/kt45461_2.kt:12:19: warning: type argument for a type parameter S can't be inferred because it has incompatible upper bounds: String, K (multiple incompatible classes: String, Int). This will become an error in a future release
     Bar<String>().takeFoo(foo) // error in 1.3.72, no error in 1.4.31
                   ^^^^^^^
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_2.fir.diag.txt

@@ -1,3 +1,3 @@
 /kt45461_2.kt:(198,201): warning: Type 'kotlin.Int' is final, so the value of the type parameter is predetermined.
 
-/kt45461_2.kt:(253,260): warning: Type argument for type parameter 'S' cannot be inferred because it has incompatible upper bounds: kotlin.String, K (multiple incompatible classes: kotlin/String, kotlin/Int). This will become an error in Kotlin 2.0.
+/kt45461_2.kt:(253,260): warning: Type argument for type parameter 'S' cannot be inferred because it has incompatible upper bounds: kotlin.String, K (multiple incompatible classes: kotlin/String, kotlin/Int). This will become an error in a future release.

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_5.diag.txt

@@ -1,4 +1,4 @@
-/kt45461_5.kt:12:19: warning: type argument for a type parameter S can't be inferred because it has incompatible upper bounds: String, K (multiple incompatible classes: String, Number). This will become an error in Kotlin 2.0
+/kt45461_5.kt:12:19: warning: type argument for a type parameter S can't be inferred because it has incompatible upper bounds: String, K (multiple incompatible classes: String, Number). This will become an error in a future release
     Bar<String>().takeFoo(foo) // error in 1.3.72, no error in 1.4.31
                   ^^^^^^^
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt45461_5.fir.diag.txt

@@ -1 +1 @@
-/kt45461_5.kt:(269,276): warning: Type argument for type parameter 'S' cannot be inferred because it has incompatible upper bounds: kotlin.String, K (multiple incompatible classes: kotlin/String, kotlin/Number). This will become an error in Kotlin 2.0.
+/kt45461_5.kt:(269,276): warning: Type argument for type parameter 'S' cannot be inferred because it has incompatible upper bounds: kotlin.String, K (multiple incompatible classes: kotlin/String, kotlin/Number). This will become an error in a future release.

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt48765.diag.txt

@@ -1,4 +1,4 @@
-/kt48765.kt:10:13: warning: type argument for a type parameter T can't be inferred because it has incompatible upper bounds: String, Number (multiple incompatible classes). This will become an error in Kotlin 2.0
+/kt48765.kt:10:13: warning: type argument for a type parameter T can't be inferred because it has incompatible upper bounds: String, Number (multiple incompatible classes). This will become an error in a future release
         B().foo(x, foo())
             ^^^
 /kt48765.kt:14:9: warning: 'String' is a final type, and thus a value of the type parameter is predetermined

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt48765.fir.diag.txt

@@ -1,4 +1,4 @@
-/kt48765.kt:(282,285): warning: Type argument for type parameter 'T' cannot be inferred because it has incompatible upper bounds: kotlin.String, kotlin.Number (multiple incompatible classes). This will become an error in Kotlin 2.0.
+/kt48765.kt:(282,285): warning: Type argument for type parameter 'T' cannot be inferred because it has incompatible upper bounds: kotlin.String, kotlin.Number (multiple incompatible classes). This will become an error in a future release.
 
 /kt48765.kt:(345,351): warning: Type 'kotlin.String' is final, so the value of the type parameter is predetermined.
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt48987.fir.kt

@@ -5,7 +5,7 @@ fun box(): String {
     return try {
         val range1 = 0..1
         range1 <!CAST_NEVER_SUCCEEDS!>as<!> List<Double>
-        range1.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_ERROR!>joinToString<!> { "" }
+        range1.<!INFERRED_TYPE_VARIABLE_INTO_EMPTY_INTERSECTION_WARNING!>joinToString<!> { "" }
     } catch (e: java.lang.ClassCastException) {
         "OK"
     }

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt49661.diag.txt

@@ -1,4 +1,4 @@
-/kt49661.kt:11:5: warning: type argument for a type parameter T can't be inferred because it has incompatible upper bounds: Foo, Int (multiple incompatible classes). This will become an error in Kotlin 2.0
+/kt49661.kt:11:5: warning: type argument for a type parameter T can't be inferred because it has incompatible upper bounds: Foo, Int (multiple incompatible classes). This will become an error in a future release
     f<Int> { g() }
     ^
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/kt49661.fir.diag.txt

@@ -1 +1 @@
-/kt49661.fir.kt:(243,244): warning: Type argument for type parameter 'T' cannot be inferred because it has incompatible upper bounds: Foo, kotlin.Int (multiple incompatible classes). This will become an error in Kotlin 2.0.
+/kt49661.fir.kt:(243,244): warning: Type argument for type parameter 'T' cannot be inferred because it has incompatible upper bounds: Foo, kotlin.Int (multiple incompatible classes). This will become an error in a future release.

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/selectFromCovariantAndContravariantTypes.diag.txt

@@ -1,4 +1,4 @@
-/selectFromCovariantAndContravariantTypes.kt:17:5: warning: type argument for a type parameter V can't be inferred because it has incompatible upper bounds: A, B (multiple incompatible classes). This will become an error in Kotlin 2.0
+/selectFromCovariantAndContravariantTypes.kt:17:5: warning: type argument for a type parameter V can't be inferred because it has incompatible upper bounds: A, B (multiple incompatible classes). This will become an error in a future release
     genericIn(select(a, b))
     ^^^^^^^^^
 

compiler/testData/diagnostics/tests/inference/emptyIntersectionTypes/selectFromCovariantAndContravariantTypes.fir.diag.txt

@@ -1 +1 @@
-/selectFromCovariantAndContravariantTypes.kt:(335,344): warning: Type argument for type parameter 'V' cannot be inferred because it has incompatible upper bounds: A, B (multiple incompatible classes). This will become an error in Kotlin 2.0.
+/selectFromCovariantAndContravariantTypes.kt:(335,344): warning: Type argument for type parameter 'V' cannot be inferred because it has incompatible upper bounds: A, B (multiple incompatible classes). This will become an error in a future release.