Change policy with legacy compiler backend

[JS] Remove incremental js jps test

[JS] Remove test of maven js archetype

[JS] Fix another one test

[JS] Fix tests for jps

[JS] Try to fix maven test data

[JS] Fix test data

[JS] Fix test data for ant

[JS] Fix jsExtraHelp test

[JS] Fix test run from not-Gradle build tools

[JS] Set flag without compiler error

[JS] Disable warnings and errors in legacy compiler called from Gradle

[JS] Proofread messages

[JS] Not proofread messages

KT-42326

compiler/incremental-compilation-impl/test/org/jetbrains/kotlin/incremental/AbstractIncrementalJsCompilerRunnerTest.kt

@@ -42,6 +42,7 @@ abstract class AbstractIncrementalJsCompilerRunnerTest : AbstractIncrementalComp
             outputFile = File(destinationDir, "${testDir.name}.js").path
             sourceMap = true
             metaInfo = true
+            useDeprecatedLegacyCompiler = true
         }
 
     protected open val scopeExpansionMode = CompileScopeExpansionMode.NEVER

compiler/incremental-compilation-impl/test/org/jetbrains/kotlin/incremental/AbstractIncrementalMultiModuleJsCompilerRunnerTest.kt

@@ -28,6 +28,7 @@ abstract class AbstractIncrementalMultiModuleJsCompilerRunnerTest :
         K2JSCompilerArguments().apply {
             sourceMap = true
             metaInfo = true
+            useDeprecatedLegacyCompiler = true
         }
 
     override fun makeForSingleModule(