Enable host multilib for ART testing.

(cherry picked from commit 13713826a6bde410bfb409059c841c58d6921f3c)

Change-Id: I11b7a5088316b4d87cb877035fde09d7b7c58b7a
am c831c726: Merge "Enable host multilib for ART testing."

* commit 'c831c726067e0d8a05362e710e2405f0eff81e07':
  Enable host multilib for ART testing.
ARM64: Fix fdlibm compilation flags.

Currently fdlibm is compiled using the default C standard (gnu99).
This specifies a relaxed floating point model that enables fused
operations such as fused multiply-add (-ffp-contract=fast).

Since fdlibm is used to compute StrictMath operations this is too
permissive on targets that have support for fused operations such as
ARM64.

bug: 17663117
Signed-off-by: Serban Constantinescu <serban.constantinescu@arm.com>

(cherry picked from commit 0eb593375b6e890846eedbf08ee6901e1d73beba)

Change-Id: I713acb6b273787ae70ce1d664bea012b0a347ccb
am 8b08bde1: Merge "ARM64: Fix fdlibm compilation flags."

* commit '8b08bde15b80b40d3cbb731f5415434fc843d800':
  ARM64: Fix fdlibm compilation flags.
am a418ed72: ARM64: Fix fdlibm compilation flags.

* commit 'a418ed7226f330c2506ff420274a8a289fd2f73c':
  ARM64: Fix fdlibm compilation flags.