[K/JS] Add flag for disabling signature uniqueness checks at klib generating phase

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/CommonCompilerArguments.kt

@@ -422,6 +422,12 @@ abstract class CommonCompilerArguments : CommonToolArguments() {
     )
     var normalizeAbsolutePath: Boolean by FreezableVar(false)
 
+    @Argument(
+        value = "-Xklib-enable-signature-clash-checks",
+        description = "Enable the checks on uniqueness of signatures"
+    )
+    var enableSignatureClashChecks: Boolean by FreezableVar(true)
+
     @Argument(value = "-Xenable-incremental-compilation", description = "Enable incremental compilation")
     var incrementalCompilation: Boolean? by FreezableVar(null)
 

compiler/cli/cli-js/src/org/jetbrains/kotlin/cli/js/K2JsIrCompiler.kt

@@ -216,6 +216,7 @@ class K2JsIrCompiler : CLICompiler<K2JSCompilerArguments>() {
         }
 
         configuration.put(CommonConfigurationKeys.KLIB_NORMALIZE_ABSOLUTE_PATH, arguments.normalizeAbsolutePath)
+        configuration.put(CommonConfigurationKeys.PRODUCE_KLIB_SIGNATURES_CLASH_CHECKS, arguments.enableSignatureClashChecks)
 
         val environmentForJS =
             KotlinCoreEnvironment.createForProduction(rootDisposable, configuration, EnvironmentConfigFiles.JS_CONFIG_FILES)