[gcc r14-7411] gccrs: Add missing known attribute stable

[Arthur Cohen]

https://gcc.gnu.org/g:e275538169881fecbb8a347b71b2130ebf2f3cf5

commit r14-7411-ge275538169881fecbb8a347b71b2130ebf2f3cf5
Author: Philip Herron <herron.philip@googlemail.com>
Date:   Wed Mar 29 16:49:40 2023 +0100

    gccrs: Add missing known attribute stable
    
    Fixes #2025
    
    gcc/rust/ChangeLog:
    
            * util/rust-attributes.cc: Add stable to the table of known attributes
    
    Signed-off-by: Philip Herron <herron.philip@googlemail.com>

Diff:
---
 gcc/rust/util/rust-attributes.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/rust/util/rust-attributes.cc b/gcc/rust/util/rust-attributes.cc
index 55f3aa21ef6..941d4459bd4 100644
--- a/gcc/rust/util/rust-attributes.cc
+++ b/gcc/rust/util/rust-attributes.cc
@@ -46,7 +46,8 @@ static const BuiltinAttrDefinition __definitions[]
      {"target_feature", CODE_GENERATION},
      // From now on, these are reserved by the compiler and gated through
      // #![feature(rustc_attrs)]
-     {"rustc_inherit_overflow_checks", CODE_GENERATION}};
+     {"rustc_inherit_overflow_checks", CODE_GENERATION},
+     {"stable", STATIC_ANALYSIS}};
 
 BuiltinAttributeMappings *
 BuiltinAttributeMappings::get ()