tree 2dde51f9c78ae2adbe070961b8643d0c035978f0
parent b3c2154f2afc419c8d6bc92c812eff0113e9f692
author Stephen Crane <sjc@immunant.com> 1494369875 -0700
committer Stephen Crane <sjc@immunant.com> 1502826852 -0700

Add LTO support to soong

Enabling the lto property for a module builds that module and all static
dependencies with LTO.

LTO (link-time optimization) allows the compiler to optimize and
generate code for the entire module at link time, rather than
per-compilation unit. LTO is required for Clang CFI and other
whole-program optimization techniques. LTO also allows cross-compilation
unit optimizations that should result in faster and smaller code, at the
expense of additional compilation time.

Test: make -j12 libc with lto: true for libc

Change-Id: Ib8baefedf60e02701d44673a7c473e0845730101