[FIR] Downgrade some extra checkers to experimentals

- `EmptyRangeChecker.kt`
    - inaccurate: compares function names as strings
        - has false positives on user-defined functions
- `RedundantInterpolationPrefixChecker.kt`
    - inaccurate: I'm not sure I trust the specified regex, especially
      in the case of multidollar interpolation
        - it also describes some strange `$` followed by \` and then
          non-\`s

^KT-69938

Author: lunakoly

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/ExperimentalExpressionCheckers.kt

@@ -5,6 +5,22 @@
 
 package org.jetbrains.kotlin.fir.analysis.checkers
 
+import org.jetbrains.kotlin.fir.analysis.checkers.experimental.*
 import org.jetbrains.kotlin.fir.analysis.checkers.expression.*
 
-object ExperimentalExpressionCheckers : ExpressionCheckers()
+object ExperimentalExpressionCheckers : ExpressionCheckers() {
+    override val functionCallCheckers: Set<FirFunctionCallChecker>
+        get() = setOf(
+            EmptyRangeChecker,
+        )
+
+    override val stringConcatenationCallCheckers: Set<FirStringConcatenationCallChecker>
+        get() = setOf(
+            RedundantInterpolationPrefixCheckerConcatenation,
+        )
+
+    override val literalExpressionCheckers: Set<FirLiteralExpressionChecker>
+        get() = setOf(
+            RedundantInterpolationPrefixCheckerLiteral,
+        )
+}

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/ExtraExpressionCheckers.kt

@@ -27,18 +27,11 @@ object ExtraExpressionCheckers : ExpressionCheckers() {
 
     override val functionCallCheckers: Set<FirFunctionCallChecker>
         get() = setOf(
-            EmptyRangeChecker,
             PlatformClassMappedToKotlinConstructorCallChecker,
         )
 
     override val stringConcatenationCallCheckers: Set<FirStringConcatenationCallChecker>
         get() = setOf(
             RedundantSingleExpressionStringTemplateChecker,
-            RedundantInterpolationPrefixCheckerConcatenation,
-        )
-
-    override val literalExpressionCheckers: Set<FirLiteralExpressionChecker>
-        get() = setOf(
-            RedundantInterpolationPrefixCheckerLiteral,
         )
 }

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/extra/EmptyRangeChecker.kt renamed to compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/experimental/EmptyRangeChecker.kt

@@ -1,9 +1,9 @@
 /*
- * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2024 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package org.jetbrains.kotlin.fir.analysis.checkers.extra
+package org.jetbrains.kotlin.fir.analysis.checkers.experimental
 
 import org.jetbrains.kotlin.KtFakeSourceElementKind
 import org.jetbrains.kotlin.diagnostics.DiagnosticReporter

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/extra/RedundantInterpolationPrefixChecker.kt renamed to compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/experimental/RedundantInterpolationPrefixCheckerLiteral.kt

@@ -3,7 +3,7 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package org.jetbrains.kotlin.fir.analysis.checkers.extra
+package org.jetbrains.kotlin.fir.analysis.checkers.experimental
 
 import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.diagnostics.reportOn

compiler/testData/diagnostics/tests/EnabledMultiDollarInterpolation.fir.kt

@@ -1,5 +1,5 @@
 // LANGUAGE: +MultiDollarInterpolation
-// WITH_EXTRA_CHECKERS
+// WITH_EXPERIMENTAL_CHECKERS
 // DIAGNOSTICS: -warnings +REDUNDANT_INTERPOLATION_PREFIX
 // WITH_STDLIB
 

compiler/testData/diagnostics/tests/EnabledMultiDollarInterpolation.kt

@@ -1,5 +1,5 @@
 // LANGUAGE: +MultiDollarInterpolation
-// WITH_EXTRA_CHECKERS
+// WITH_EXPERIMENTAL_CHECKERS
 // DIAGNOSTICS: -warnings +REDUNDANT_INTERPOLATION_PREFIX
 // WITH_STDLIB
 

compiler/testData/diagnostics/tests/IncorrectMultiDollarInterpolationCodeA.fir.kt

@@ -1,5 +1,5 @@
 // LANGUAGE: +MultiDollarInterpolation
-// WITH_EXTRA_CHECKERS
+// WITH_EXPERIMENTAL_CHECKERS
 // DIAGNOSTICS: -warnings +REDUNDANT_INTERPOLATION_PREFIX
 // WITH_STDLIB
 

compiler/testData/diagnostics/tests/IncorrectMultiDollarInterpolationCodeA.kt

@@ -1,5 +1,5 @@
 // LANGUAGE: +MultiDollarInterpolation
-// WITH_EXTRA_CHECKERS
+// WITH_EXPERIMENTAL_CHECKERS
 // DIAGNOSTICS: -warnings +REDUNDANT_INTERPOLATION_PREFIX
 // WITH_STDLIB
 

compiler/testData/diagnostics/tests/IncorrectPaddedMultiDollarInterpolationCodeA.fir.kt

@@ -1,5 +1,5 @@
 // LANGUAGE: +MultiDollarInterpolation
-// WITH_EXTRA_CHECKERS
+// WITH_EXPERIMENTAL_CHECKERS
 // DIAGNOSTICS: -warnings +REDUNDANT_INTERPOLATION_PREFIX
 // WITH_STDLIB
 

compiler/testData/diagnostics/tests/IncorrectPaddedMultiDollarInterpolationCodeA.kt

@@ -1,5 +1,5 @@
 // LANGUAGE: +MultiDollarInterpolation
-// WITH_EXTRA_CHECKERS
+// WITH_EXPERIMENTAL_CHECKERS
 // DIAGNOSTICS: -warnings +REDUNDANT_INTERPOLATION_PREFIX
 // WITH_STDLIB