Remove macro role trailing comma support

Author: mateusrodriguesxyz

lib/Parse/ParseDecl.cpp

@@ -2551,7 +2551,7 @@ Parser::parseMacroRoleAttribute(
   SmallVector<TypeExpr *, 2> conformances;
   auto argumentsStatus = parseList(
       tok::r_paren, lParenLoc, rParenLoc,
-      /*AllowSepAfterLast=*/true, diag::expected_rparen_expr_list, [&] {
+      /*AllowSepAfterLast=*/false, diag::expected_rparen_expr_list, [&] {
         ParserStatus status;
 
         if (consumeIf(tok::code_complete)) {

test/Parse/trailing-comma.swift

@@ -57,11 +57,6 @@ struct S {
     #foo(1, 2,)
 }
 
-// Macro Role Attribute
-
-@attached(extension, conformances: OptionSet,)
-macro OptionSet<RawType>() = #externalMacro(module: "SwiftMacros", type: "OptionSetMacro")
-
 // String Literal Interpolation
 
 "\(1,)"
@@ -74,6 +69,9 @@ if #available(iOS 15,) { }  // expected-error {{expected platform name}}
 
 // Built-in Attributes
 
+@attached(extension, conformances: OptionSet,)  // expected-error {{unexpected ',' separator}}
+macro OptionSet<RawType>() = #externalMacro(module: "SwiftMacros", type: "OptionSetMacro")
+
 @inline(never,) // expected-error {{expected declaration}} expected-error {{expected ')' in 'inline' attribute}} 
 func foo() { }