Move target specific GCC code generation options
Move target specific GCC code generation options

Move "-fno-delete-null-pointer-checks -fconserve-stack" to the
target-only portion of the CFLAGS as they are no needed for host tools
(and not supported by clang).

Signed-off-by: Vincent Palatin <70a9964ec8fd10b0b08fcc8623c2add25ddf99ac@chromium.org>

BRANCH=none
BUG=chromium:475960
TEST=make utils-host V=1
make BOARD=samus_pd V=1
and manually check the compilation flags

Change-Id: I001359621d60b5ad4e020f41fe2e97d4b7edec2a
Reviewed-on: https://chromium-review.googlesource.com/266212
Reviewed-by: Randall Spangler <62698fdbb84d1779579ee80c3f39fac22017e5bc@chromium.org>
Commit-Queue: Vincent Palatin <70a9964ec8fd10b0b08fcc8623c2add25ddf99ac@chromium.org>
Trybot-Ready: Vincent Palatin <70a9964ec8fd10b0b08fcc8623c2add25ddf99ac@chromium.org>
Tested-by: Vincent Palatin <70a9964ec8fd10b0b08fcc8623c2add25ddf99ac@chromium.org>

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