configure: correctly discover -W options for clang
commitc9fd7b2aa5086205a626f8312bbaa5043b72a6d7
authorH. Peter Anvin <hpa@zytor.com>
Tue, 17 May 2016 04:35:48 +0000 (16 21:35 -0700)
committerH. Peter Anvin <hpa@zytor.com>
Tue, 17 May 2016 04:35:48 +0000 (16 21:35 -0700)
tree1850c6a6c767c122ca13c8fe45aa08eeb12afe83
parentacbf8f0e1972eb690c91c5bca5b8c1c960dde4b5
configure: correctly discover -W options for clang

clang doesn't error out on unknown -W options unless
-Werror=unknown-warning-option is specified first, so do that so the
configure script can do its job.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
configure.in