FE: split test "buildList type argument is inferred into upper bound"

Related to KT-50520, KT-56169

compiler/testData/diagnostics/testsWithStdLib/builderInference/buildListToUpperBound.fir.kt

@@ -1,5 +1,6 @@
 // WITH_STDLIB
-// SKIP_TXT
+// !LANGUAGE: -ForbidInferringPostponedTypeVariableIntoDeclaredUpperBound
+// ISSUE: KT-50520
 
 fun box(): String {
     <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>buildList<!> {

compiler/testData/diagnostics/testsWithStdLib/builderInference/buildListToUpperBound.kt

@@ -0,0 +1,11 @@
+// WITH_STDLIB
+// !LANGUAGE: -ForbidInferringPostponedTypeVariableIntoDeclaredUpperBound
+// ISSUE: KT-50520
+
+fun box(): String {
+    buildList {
+        val foo = { first() }
+        add(0, foo)
+    }
+    return "OK"
+}

compiler/testData/diagnostics/testsWithStdLib/builderInference/buildListToUpperBoundForbidden.fir.kt

@@ -0,0 +1,11 @@
+// WITH_STDLIB
+// !LANGUAGE: +ForbidInferringPostponedTypeVariableIntoDeclaredUpperBound
+// ISSUE: KT-56169
+
+fun box(): String {
+    <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>buildList<!> {
+        val foo = { first() }
+        add(0, foo)
+    }
+    return "OK"
+}

compiler/testData/diagnostics/testsWithStdLib/builderInference/buildListToUpperBoundForbidden.kt

@@ -1,5 +1,6 @@
 // WITH_STDLIB
-// SKIP_TXT
+// !LANGUAGE: +ForbidInferringPostponedTypeVariableIntoDeclaredUpperBound
+// ISSUE: KT-56169
 
 fun box(): String {
     <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>buildList<!> {