[gcc r14-7695] rust: Add -frust-name-resolution-2.0 option

[Arthur Cohen]

https://gcc.gnu.org/g:3381f522f206f3b64a973976f422b283dd9f49e6

commit r14-7695-g3381f522f206f3b64a973976f422b283dd9f49e6
Author: Arthur Cohen <arthur.cohen@embecosm.com>
Date:   Tue Jun 20 02:22:57 2023 +0200

    rust: Add -frust-name-resolution-2.0 option
    
    This option enables an experimental name resolution algorithm. Disabled
    by default.
    
    gcc/rust/ChangeLog:
    
            * lang.opt: Add -frust-name-resolution-2.0 option

Diff:
---
 gcc/rust/lang.opt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/gcc/rust/lang.opt b/gcc/rust/lang.opt
index 4a6a011c660..2af0f1a9bf9 100644
--- a/gcc/rust/lang.opt
+++ b/gcc/rust/lang.opt
@@ -167,4 +167,8 @@ Enum(frust_compile_until) String(compilation) Value(9)
 EnumValue
 Enum(frust_compile_until) String(end) Value(10)
 
+frust-name-resolution-2.0
+Rust Var(flag_name_resolution_2_0)
+Use the temporary and experimental name resolution pipeline instead of the stable one
+
 ; This comment is to ensure we retain the blank line above.