Fixed handling of CFLAGS for specifying platform specific options.

Now use AM_CFLAGS so we don't override user options.

    * Makefile.in: Regenerated
    * analysis/Makefile.in: Regenerated
    * configure: Regenerated
    * configure.ac: Changed substitutions for CFLAGS to AM_CFLAGS
    * src/2dfir/Makefile.in: Regenerated
    * src/adpcm/Makefile.in: Regenerated
    * src/blowfish/Makefile.in: Regenerated
    * src/bs/Makefile.in: Regenerated
    * src/bubblesort/Makefile.in: Regenerated
    * src/cnt/Makefile.in: Regenerated
    * src/common.mk.am: Append to AM_CFLAGS instead of set
    * src/compress/Makefile.in: Regenerated
    * src/crc32/Makefile.in: Regenerated
    * src/cubic/Makefile.in: Regenerated
    * src/dijkstra/Makefile.in: Regenerated
    * src/duff/Makefile.in: Regenerated
    * src/edn/Makefile.in: Regenerated
    * src/fasta/Makefile.in: Regenerated
    * src/fdct/Makefile.in: Regenerated
    * src/fft/Makefile.in: Regenerated
    * src/float_matmult/Makefile.in: Regenerated
    * src/gdb-advance/Makefile.in: Regenerated
    * src/gdb-all-types/Makefile.in: Regenerated
    * src/gdb-anon/Makefile.in: Regenerated
    * src/gdb-arrayidx/Makefile.in: Regenerated
    * src/gdb-async/Makefile.in: Regenerated
    * src/int_matmult/Makefile.in: Regenerated
    * src/lms/Makefile.in: Regenerated
    * src/nbody/Makefile.in: Regenerated
    * src/platformcode/Makefile.in: Regenerated
    * src/rijndael/Makefile.in: Regenerated
    * src/sha/Makefile.in: Regenerated
    * src/template/Makefile.in: Regenerated