configure: Disable -Wtautological-type-limit-compare

Clang 10 enables this by default with -Wtype-limit.

All of the instances flagged by this Werror so far have been
cases in which we really do want the compiler to optimize away
the test completely.  Disabling the warning will avoid having
to add ifdefs to work around this.

Cc: Eric Blake <[email protected]>
Buglink: https://bugs.launchpad.net/qemu/+bug/1878628
Acked-by: Thomas Huth <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Reviewed-by: Alex Bennée <[email protected]>
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Signed-off-by: Richard Henderson <[email protected]>
Message-id: [email protected]
Signed-off-by: Peter Maydell <[email protected]>

Author: rth7680

configure

@@ -2054,6 +2054,7 @@ add_to nowarn_flags -Wno-missing-include-dirs
 add_to nowarn_flags -Wno-shift-negative-value
 add_to nowarn_flags -Wno-string-plus-int
 add_to nowarn_flags -Wno-typedef-redefinition
+add_to nowarn_flags -Wno-tautological-type-limit-compare
 
 gcc_flags="$warn_flags $nowarn_flags"