Allow only 'out' modifier for value parameter modifiers in functional type

(comments also mention 'lazy' and 'ref'; these value parameter modifiers are unsupported, anyway).

compiler/frontend/src/org/jetbrains/kotlin/lexer/KtTokens.java

@@ -232,6 +232,7 @@ public interface KtTokens {
 
     TokenSet TYPE_MODIFIER_KEYWORDS = TokenSet.create(SUSPEND_KEYWORD);
     TokenSet TYPE_ARGUMENT_MODIFIER_KEYWORDS = TokenSet.create(IN_KEYWORD, OUT_KEYWORD);
+    TokenSet RESERVED_VALUE_PARAMETER_MODIFIER_KEYWORDS = TokenSet.create(OUT_KEYWORD); // lazy, out, ref
 
     TokenSet VISIBILITY_MODIFIERS = TokenSet.create(PRIVATE_KEYWORD, PUBLIC_KEYWORD, INTERNAL_KEYWORD, PROTECTED_KEYWORD);
 

compiler/frontend/src/org/jetbrains/kotlin/parsing/KotlinParsing.java

@@ -461,6 +461,10 @@ public class KotlinParsing extends AbstractKotlinParsing {
         return doParseModifierList(tokenConsumer, MODIFIER_KEYWORDS, annotationParsingMode, noModifiersBefore);
     }
 
+    private boolean parseValueParameterModifierList() {
+        return doParseModifierList(null, RESERVED_VALUE_PARAMETER_MODIFIER_KEYWORDS, DEFAULT, NO_MODIFIER_BEFORE_FOR_VALUE_PARAMETER);
+    }
+
     private boolean parseTypeModifierList() {
         return doParseModifierList(null, TYPE_MODIFIER_KEYWORDS, DEFAULT, TokenSet.EMPTY);
     }
@@ -2192,7 +2196,7 @@ public class KotlinParsing extends AbstractKotlinParsing {
                 if (isFunctionTypeContents) {
                     if (!tryParseValueParameter(typeRequired)) {
                         PsiBuilder.Marker valueParameter = mark();
-                        parseModifierList(DEFAULT, NO_MODIFIER_BEFORE_FOR_VALUE_PARAMETER); // lazy, out, ref
+                        parseValueParameterModifierList(); // lazy, out, ref
                         parseTypeRef();
                         closeDeclarationWithCommentBinders(valueParameter, VALUE_PARAMETER, false);
                     }