[gcc r15-4492] diagnostics: remove forward decl of json::value from diagnostic.h

[David Malcolm]

https://gcc.gnu.org/g:83abdb041426b7490e93c3f77be93148bcd94de3

commit r15-4492-g83abdb041426b7490e93c3f77be93148bcd94de3
Author: David Malcolm <dmalcolm@redhat.com>
Date:   Fri Oct 18 21:51:39 2024 -0400

    diagnostics: remove forward decl of json::value from diagnostic.h
    
    I believe this hasn't been necessary since r15-1413-gd3878c85f331c7.
    
    gcc/ChangeLog:
            * diagnostic.h (json::value): Remove forward decl.
    
    Signed-off-by: David Malcolm <dmalcolm@redhat.com>

Diff:
---
 gcc/diagnostic.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/gcc/diagnostic.h b/gcc/diagnostic.h
index edd221f1a8ce..423e07230a65 100644
--- a/gcc/diagnostic.h
+++ b/gcc/diagnostic.h
@@ -220,7 +220,6 @@ public:
 };
 
 class edit_context;
-namespace json { class value; }
 class diagnostic_client_data_hooks;
 class logical_location;
 class diagnostic_diagram;