Multilib ART host.

Build ART for the host as a multilib project with dalvikvm32 and dalvikvm64
running as 32 or 64-bit repsectfully. Note, currently multilib host builds
are not the default, you make the so by setting BUILD_HOST_64bit=1.
Extend tests to execute in both 32 and 64-bit modes. By default both 32 and
64-bit tests are run, add 32 or 64 to the end of a test name to run it in
purely that flavor.
Given the extra spam, modify oat tests to only generate console output when
the test fails.
Change the test harness so that common commands are run when a test should be
skipped, when it passes or when it fails. Use these commands to generate a
summary of passing, skipped and failing tests. Tests will be skipped if they
are known to be broken or if a test has already failed. Setting the variable
TEST_ART_KEEP_GOING=true will force working tests not to be skipped.
In this change all tests running on the optimizing compiler are marked broken
due to breakages running them in a multilib environment.
Break apart Android.common.mk into its constituent parts, along with other
pieces of reorganization.

Stylistic nit, we refer to make rule targets as targets thereby overloading
the term target. While consistent with make's terminology, its confusing with
the Android notion of target. I've switched to just calling targets rules to
avoid confusion in host tests.

Change-Id: I5190fc3de46800a949fbb06b3f4c258ca89ccde9
21 files changed