C++ PATCH for c++/83820 - excessive attribute arguments not detected

[Dominique d'Humières]

On darwin* I see

FAIL: g++.dg/cpp0x/gen-attrs-67.C  -std=c++14 (test for excess errors)
FAIL: g++.dg/cpp0x/gen-attrs-67.C  -std=c++17 (test for excess errors)

This is caused by the additional error

/opt/gcc/_clean/gcc/testsuite/g++.dg/cpp0x/gen-attrs-67.C:11:34: error: constructor priorities are not supported
   11 | [[gnu::constructor(101)]] int f7();

and it is fixed by the following patch

--- ../_clean/gcc/testsuite/g++.dg/cpp0x/gen-attrs-67.C	2019-06-17 20:33:15.000000000 +0200
+++ gcc/testsuite/g++.dg/cpp0x/gen-attrs-67.C	2019-06-20 18:13:13.000000000 +0200
@@ -8,4 +8,4 @@
 [[nodiscard()]] int f4(); // { dg-error ".nodiscard. attribute does not take any arguments" }
 [[gnu::noinline()]] int f5(); // { dg-error ".noinline. attribute does not take any arguments" }
 [[gnu::constructor]] int f6();
-[[gnu::constructor(101)]] int f7();
+[[gnu::constructor(101)]] int f7(); // { dg-error "constructor priorities are not supported" { target *-*-darwin* } }

Is it OK to commit it to trunk?

TIA

Dominique