assertion: Language constructor must be non-public to avoid creating Language duplicates + test

GitOrigin-RevId: eb6954f444bf64bbc1d47b419af5e4db6fadf07e

RegExpSupport/src/org/intellij/lang/regexp/ecmascript/EcmaScriptRegexpLanguage.java

@@ -12,7 +12,7 @@ public class EcmaScriptRegexpLanguage extends Language {
   public static final EcmaScriptRegexpLanguage INSTANCE = new EcmaScriptRegexpLanguage();
   public static final String ID = "JSRegexp";
 
-  public EcmaScriptRegexpLanguage() {
+  private EcmaScriptRegexpLanguage() {
     super(RegExpLanguage.INSTANCE, ID);
   }
 }

RegExpSupport/src/org/intellij/lang/regexp/ecmascript/EcmaScriptUnicodeRegexpLanguage.java

@@ -12,7 +12,7 @@ public class EcmaScriptUnicodeRegexpLanguage extends Language {
   public static final EcmaScriptUnicodeRegexpLanguage INSTANCE = new EcmaScriptUnicodeRegexpLanguage();
   public static final String ID = "JSUnicodeRegexp";
 
-  public EcmaScriptUnicodeRegexpLanguage() {
+  private EcmaScriptUnicodeRegexpLanguage() {
     super(RegExpLanguage.INSTANCE, ID);
   }
 }

images/src/org/intellij/images/fileTypes/impl/SvgLanguage.kt

@@ -9,7 +9,7 @@ import com.intellij.psi.impl.source.xml.XmlFileImpl
 import com.intellij.psi.tree.IFileElementType
 import org.jetbrains.annotations.NotNull
 
-class SvgLanguage : XMLLanguage(XMLLanguage.INSTANCE, "SVG", "image/svg+xml") {
+class SvgLanguage private constructor(): XMLLanguage(XMLLanguage.INSTANCE, "SVG", "image/svg+xml") {
   companion object {
     @JvmField
     val INSTANCE = SvgLanguage()

java/jsp-base-openapi/src/com/intellij/lang/jsp/JspxFileViewProvider.java

@@ -10,7 +10,7 @@ public interface JspxFileViewProvider extends TemplateLanguageFileViewProvider {
   Language JAVA_HOLDER_METHOD_TREE_LANGUAGE = new JavaHolderMethodTreeLanguage();
 
   class JavaHolderMethodTreeLanguage extends Language implements DependentLanguage{
-    public JavaHolderMethodTreeLanguage() {
+    JavaHolderMethodTreeLanguage() {
       super("JAVA_HOLDER_METHOD_TREE", "");
     }
   }

java/manifest/src/org/jetbrains/lang/manifest/ManifestLanguage.java

@@ -32,7 +32,7 @@ import com.intellij.lang.Language;
 public class ManifestLanguage extends Language {
   public static final ManifestLanguage INSTANCE = new ManifestLanguage();
 
-  public ManifestLanguage() {
+  private ManifestLanguage() {
     super("Manifest");
   }
 }

plugins/properties/properties-psi-api/src/com/intellij/lang/properties/PropertiesLanguage.java

@@ -6,7 +6,7 @@ import com.intellij.lang.Language;
 public class PropertiesLanguage extends Language {
   public static final PropertiesLanguage INSTANCE = new PropertiesLanguage();
 
-  public PropertiesLanguage() {
+  private PropertiesLanguage() {
     super("Properties", "text/properties");
   }
 }

plugins/sh/core/src/com/intellij/sh/ShLanguage.java

@@ -8,7 +8,7 @@ import com.intellij.notification.NotificationGroupManager;
 public final class ShLanguage extends Language {
   public static final Language INSTANCE = new ShLanguage();
 
-  public ShLanguage() {
+  private ShLanguage() {
     super("Shell Script", "application/x-bsh", "application/x-sh", "text/x-script.sh");
   }
 }

python/src/com/jetbrains/python/codeInsight/regexp/PythonRegexpLanguage.java

@@ -8,7 +8,7 @@ import org.intellij.lang.regexp.RegExpLanguage;
 public class PythonRegexpLanguage extends Language {
   public static final PythonRegexpLanguage INSTANCE = new PythonRegexpLanguage();
 
-  public PythonRegexpLanguage() {
+  private PythonRegexpLanguage() {
     super(RegExpLanguage.INSTANCE, "PythonRegExp");
   }
 }

python/src/com/jetbrains/python/codeInsight/regexp/PythonVerboseRegexpLanguage.java

@@ -9,7 +9,7 @@ import org.intellij.lang.regexp.RegExpLanguage;
 public class PythonVerboseRegexpLanguage extends Language {
   public static final PythonVerboseRegexpLanguage INSTANCE = new PythonVerboseRegexpLanguage();
 
-  public PythonVerboseRegexpLanguage() {
+  private PythonVerboseRegexpLanguage() {
     super(RegExpLanguage.INSTANCE, PyNames.VERBOSE_REG_EXP_LANGUAGE_ID);
   }
 }

xml/xml-psi-api/src/com/intellij/lang/html/HtmlCompatibleMetaLanguage.java

@@ -25,7 +25,7 @@ public class HtmlCompatibleMetaLanguage extends MetaLanguage {
       () -> ContainerUtil.map2Set(EP_NAME.getExtensionList(), e -> e.language)
     ), EP_NAME, null);
 
-  public HtmlCompatibleMetaLanguage() {
+  private HtmlCompatibleMetaLanguage() {
     super("HtmlCompatible");
   }