[pushed] [gdb/build, clang] Fix ignored aligned attribute

[Tom de Vries <tdevries@suse.de>]

PR build/34279 reports a build failure with clang.

This is a regression since commit 6c85ef111b0 ("[gdb] Use using instead of
typedef"), which did:
...
-typedef long __attribute__ ((__aligned__ (4))) compat_x32_clock_t;
+using compat_x32_clock_t = long __attribute__ ((__aligned__ (4)));
...

The problem is that clang ignores the attribute.

Fix this by reverting this part of the commit.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=34279
---
 gdb/nat/amd64-linux-siginfo.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/nat/amd64-linux-siginfo.c b/gdb/nat/amd64-linux-siginfo.c
index 8f1e4acc47e..99faccabf37 100644
--- a/gdb/nat/amd64-linux-siginfo.c
+++ b/gdb/nat/amd64-linux-siginfo.c
@@ -203,7 +203,7 @@ struct compat_siginfo_t
 };
 
 /* For x32, clock_t in _sigchld is 64bit aligned at 4 bytes.  */
-using compat_x32_clock_t = long __attribute__ ((__aligned__ (4)));
+typedef long __attribute__ ((__aligned__ (4))) compat_x32_clock_t;
 
 struct __attribute__ ((__aligned__ (8))) compat_x32_siginfo_t
 {

base-commit: 4cdc9a9d93571737476034869dd8caaecb5ca35d
-- 
2.51.0