Support allow_discard.

Author: webbju

UnrealAngelscriptParser/Grammar/UnrealAngelscriptLexer.g4

@@ -87,6 +87,12 @@ Bool: 'bool';
 
 /* UnrealAngelscript */
 
+NoDiscard: 'no_discard';
+
+AllowDiscard: 'allow_discard';
+
+AcceptTemporaryThis: 'accept_temporary_this';
+
 UClass: 'UCLASS';
 
 UStruct: 'USTRUCT';
@@ -109,8 +115,6 @@ Check: 'check';
 
 Auto: 'auto';
 
-AcceptTemporaryThis: 'accept_temporary_this';
-
 Access: 'access';
 
 Break: 'break';
@@ -153,8 +157,6 @@ Inherited: 'inherited';
 
 Namespace: 'namespace';
 
-NoDiscard: 'no_discard';
-
 Nullptr: 'nullptr';
 
 Operator: 'operator';

UnrealAngelscriptParser/Grammar/UnrealAngelscriptParser.g4

@@ -58,7 +58,7 @@ ufunction:
 
 moduleImport:
 	Import Identifier (Dot Identifier)* Semi
-	| Import declSpecifierSeq? declarator postFuncSpecifierSeq? From StringLiteral Semi
+	| Import declSpecifierSeq? declarator virtualSpecifierSeq? From StringLiteral Semi
 	;
 
 asGeneric:
@@ -451,7 +451,7 @@ parameterDeclaration:
 	declSpecifierSeq Identifier? (Assign initializerClause)?;
 
 functionDefinition:
-	ufunction? (accessSpecifier | accessPattern)? Mixin? declSpecifierSeq? declarator postFuncSpecifierSeq? functionBody;
+	ufunction? (accessSpecifier | accessPattern)? Mixin? declSpecifierSeq? declarator virtualSpecifierSeq? angelscriptModifierSeq? functionBody;
 
 functionBody:
 	compoundStatement
@@ -514,15 +514,24 @@ memberDeclaratorList:
 
 memberDeclarator:
 	declarator (
-		postFuncSpecifierSeq?
+		virtualSpecifierSeq? angelscriptModifierSeq?
 		| braceOrEqualInitializer?
 	)
 	| Identifier? Colon constantExpression
 	| Identifier;
 
-postFuncSpecifierSeq: virtualSpecifier+;
+virtualSpecifierSeq: virtualSpecifier+;
 
-virtualSpecifier: Override | Final | Property;
+virtualSpecifier
+    : Override
+    | Final
+    | Property // Angelscript
+    ;
+
+angelscriptModifierSeq: angelscriptModifier+;
+
+angelscriptModifier:
+	NoDiscard | AllowDiscard;
 
 /*Derived classes*/