- don't hardcode -O3

Index: build.sh
--- build.sh.orig
+++ build.sh
@@ -60,7 +60,7 @@ if [ "$parallel" -gt 1 ]; then
   fi
   CC="sem -j $parallel --id $$ ${CC}"
 fi
-COMP_FLAGS="${CPPFLAGS:-} ${CFLAGS:-} -w -fmax-errors=3 -O3 -fno-strict-aliasing -fno-ident $extraBuildArgs"
+COMP_FLAGS="${CPPFLAGS:-} ${CFLAGS:-} -w -fmax-errors=3 -fno-strict-aliasing -fno-ident $extraBuildArgs"
 LINK_FLAGS="${LDFLAGS:-} "
 PS4=""
 # platform detection
