Ensure that -fno-strict-aliasing is _appended_ after -O2
Ensure that -fno-strict-aliasing is _appended_ after -O2

-O2 includes -fstrict-aliasing, so we need to ensure that these flags
are explicitly added after each invocation. Maybe we should just use
unions instead *sigh*.

Change-Id: I9321609a671339dfe13502fdd071ad1de823bf9f
Reviewed-on: http://review.couchbase.org/43720
Tested-by: Mark Nunberg <e7d42768707bf23038325b0b68d4b577e5f6064a@haskalah.org>
Reviewed-by: Sergey Avseyev <87f6d5e4fd3644c3c20800cde7fd3ad1569370b3@gmail.com>

signmotion/libcouchbase,senthilkumaranb/libcouchbase,senthilkumaranb/libcouchbase,kojiromike/libcouchbase,PureSwift/libcouchbase,maxim-ky/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,signmotion/libcouchbase,signmotion/libcouchbase,senthilkumaranb/libcouchbase,kojiromike/libcouchbase,kojiromike/libcouchbase,signmotion/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,mnunberg/libcouchbase,PureSwift/libcouchbase,mnunberg/libcouchbase,kojiromike/libcouchbase,avsej/libcouchbase,avsej/libcouchbase,mnunberg/libcouchbase,PureSwift/libcouchbase,avsej/libcouchbase,maxim-ky/libcouchbase,senthilkumaranb/libcouchbase,avsej/libcouchbase,PureSwift/libcouchbase,avsej/libcouchbase,mody/libcouchbase,mnunberg/libcouchbase,couchbase/libcouchbase,mody/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,avsej/libcouchbase,maxim-ky/libcouchbase,maxim-ky/libcouchbase,mnunberg/libcouchbase,mody/libcouchbase,mody/libcouchbase