scons: Add '-Wl,--as-needed' to default LINKFLAGS

In current build flow, EXTRAS flag is evaluated before building gem5
tools and binaries. Such that, unneeded libraries may be linked into
gem5 binaries. Adding '-Wl,--as-needed' can fix this problem also
shrinks binaries.

Change-Id: Ifb001786a66b0dd9b29865e39a5740313002f250
Reviewed-by: Jason Lowe-Power <>
Reviewed-by: Gabe Black <>
Maintainer: Jason Lowe-Power <>
Tested-by: kokoro <>
1 file changed