Kernel: Add support for the MSG_WAITALL sys$recvmsg flag

Author: https://github.com/IdanHo
Commit: e521ffd156
Pull-request: https://github.com/SerenityOS/serenity/pull/11152
Reviewed-by: https://github.com/awesomekling

Userland/Utilities/strace.cpp

@@ -607,8 +607,8 @@ static void format_connect(FormattedSyscallBuilder& builder, int socket, const s
 struct MsgOptions : BitflagBase {
     static constexpr auto options = {
         BITFLAG(MSG_TRUNC), BITFLAG(MSG_CTRUNC), BITFLAG(MSG_PEEK),
-        BITFLAG(MSG_OOB), BITFLAG(MSG_DONTROUTE), BITFLAG(MSG_DONTWAIT)
-        // TODO: add MSG_WAITALL once its definition is added
+        BITFLAG(MSG_OOB), BITFLAG(MSG_DONTROUTE), BITFLAG(MSG_WAITALL),
+        BITFLAG(MSG_DONTWAIT)
     };
 };