[binutils-gdb] Silence -Wmaybe-uninitialized warning from target_waitstatus

[Tom Tromey <tromey@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=4536b3bb61fd2fc7b3482cdc8d03a2542cdf5d9e

commit 4536b3bb61fd2fc7b3482cdc8d03a2542cdf5d9e
Author: Tom Tromey <tromey@adacore.com>
Date:   Thu Apr 7 10:17:02 2022 -0600

    Silence -Wmaybe-uninitialized warning from target_waitstatus
    
    Currently, one use of target_waitstatus yields a warning:
    
         target/waitstatus.h: In function 'void stop_all_threads()':
         target/waitstatus.h:175:13: warning: 'ws.target_waitstatus::m_value' may be used uninitialized in this function [-Wmaybe-uninitialized]
           175 |     m_value = other.m_value;
               |     ~~~~~~~~^~~~~~~~~~~~~~~
    
    This patch silences the warning.  I tried the "volatile member"
    approach that was used for gdb::optional, but that didn't work, so
    this patch simply initializes the member.

Diff:
---
 gdb/target/waitstatus.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gdb/target/waitstatus.h b/gdb/target/waitstatus.h
index 7b5faed83c7..63bbd737749 100644
--- a/gdb/target/waitstatus.h
+++ b/gdb/target/waitstatus.h
@@ -418,7 +418,7 @@ private:
       char *execd_pathname;
       /* Syscall number */
       int syscall_number;
-    } m_value;
+    } m_value {};
 };
 
 /* Extended reasons that can explain why a target/thread stopped for a