[gcc(refs/vendors/ARM/heads/morello)] cp: Allow const __intcap decls in constexpr context

[gcc(refs/vendors/ARM/heads/morello)] cp: Allow const __intcap decls in constexpr context

[Alex Coplan]

https://gcc.gnu.org/g:028c38defced5a4e75cff07ae73e381c9d0fc51e

commit 028c38defced5a4e75cff07ae73e381c9d0fc51e
Author: Alex Coplan <alex.coplan@arm.com>
Date:   Wed Nov 16 15:46:43 2022 +0000

    cp: Allow const __intcap decls in constexpr context
    
    The testcase added with the patch was getting incorrectly rejected on
    capability targets since INTCAP_TYPE constant non-volatile declarations
    were not handled by cp/decl2.c:decl_maybe_constant_var_p.

Diff:
---
 gcc/cp/decl2.c                                              | 3 ++-
 gcc/testsuite/g++.dg/cpp0x/static_assert-const-intptr-var.C | 3 +++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index 7d406026a20..29b9c2d9f39 100644
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -4460,7 +4460,8 @@ decl_maybe_constant_var_p (tree decl)
   if (TYPE_REF_P (type))
     /* References can be constant.  */;
   else if (CP_TYPE_CONST_NON_VOLATILE_P (type)
-	   && INTEGRAL_OR_ENUMERATION_TYPE_P (type))
+	   && (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
+	    || INTCAP_TYPE_P (type)))
     /* And const integers.  */;
   else
     return false;
diff --git a/gcc/testsuite/g++.dg/cpp0x/static_assert-const-intptr-var.C b/gcc/testsuite/g++.dg/cpp0x/static_assert-const-intptr-var.C
new file mode 100644
index 00000000000..d9a0c278c67
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/static_assert-const-intptr-var.C
@@ -0,0 +1,3 @@
+// { dg-do compile { target c++11 } }
+static const __INTPTR_TYPE__ x = 1;
+static_assert (x, "should be non-zero");