Check compiler flags one at a time, otherwise one unsupported flag can invalidate others that are supported.
Check compiler flags one at a time, otherwise one unsupported flag can
invalidate others that are supported.

* configure.ac (--enable-optimization): Issue separate checks for
   -Wno-clobbered and -flto because SVN_CFLAGS_ADD_IFELSE does
   not treat its parameter as a list of options.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1480077 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion