[FIR] Report MISSING_CONSTRUCTOR_KEYWORD

^KT-59407 Fixed

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/utils/FirDeclarationUtil.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.fir.declarations.utils
 
 import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.fir.symbols.impl.FirConstructorSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
 import org.jetbrains.kotlin.fir.types.ConeClassLikeType
 import org.jetbrains.kotlin.fir.types.coneTypeSafe
@@ -68,3 +69,5 @@ val FirNamedFunctionSymbol.isMethodOfAny: Boolean
             else -> false
         }
     }
+
+val FirConstructorSymbol.isErrorPrimaryConstructor get() = fir is FirErrorPrimaryConstructor

compiler/fir/tree/src/org/jetbrains/kotlin/fir/diagnostics/ConeSimpleDiagnostic.kt

@@ -83,6 +83,10 @@ object ConeNoConstructorError : ConeDiagnostic {
     override val reason: String get() = "This type does not have a constructor"
 }
 
+object ConeMissingConstructorKeyword : ConeDiagnostic {
+    override val reason: String get() = "Use the 'constructor' keyword after the modifiers of the primary constructor."
+}
+
 enum class DiagnosticKind {
     ExpressionExpected,
     NotLoopLabel,