Add new error message - Property {0} is used before its initialization.

Author: a-tarasyuk

src/compiler/checker.ts

@@ -17478,7 +17478,7 @@ namespace ts {
             if (isInPropertyInitializer(node) &&
                 !isBlockScopedNameDeclaredBeforeUse(valueDeclaration, right)
                 && !isPropertyDeclaredInAncestorClass(prop)) {
-                diagnosticMessage = error(right, Diagnostics.Block_scoped_variable_0_used_before_its_declaration, declarationName);
+                diagnosticMessage = error(right, Diagnostics.Property_0_is_used_before_its_initialization, declarationName);
             }
             else if (valueDeclaration.kind === SyntaxKind.ClassDeclaration &&
                 node.parent.kind !== SyntaxKind.TypeReference &&

src/compiler/diagnosticMessages.json

@@ -2401,6 +2401,10 @@
         "category": "Error",
         "code": 2728
     },
+    "Property '{0}' is used before its initialization.": {
+        "category": "Error",
+        "code": 2729
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",