utils.bbclass/multilib.class: Added misc supporting functions.

1. Added variable MULTILIB_VARIANTS to store all the instance variants
for multilib extend.

2. Added function all_multilib_tune_values to collect the variable
values for all multilib instance.

3. multilib bbclass handler will save the orignal value of all variables
defined in MULTILIB_SAVE_VARNAME.

(From OE-Core rev: 18bba910e04bff75460f408e4557d4bae21ad592)

Signed-off-by: Lianhao Lu <lianhao.lu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/meta/conf/bitbake.conf b/meta/conf/bitbake.conf
index 7bb68b8dc5..b30951648d 100644
--- a/meta/conf/bitbake.conf
+++ b/meta/conf/bitbake.conf
@@ -749,3 +749,4 @@ BB_HASHTASK_WHITELIST ?= "(.*-cross$|.*-native$|.*-cross-initial$|.*-cross-inter
 BB_HASHBASE_WHITELIST ?= "TMPDIR FILE PATH PWD BB_TASKHASH BBPATH DL_DIR SSTATE_DIR THISDIR FILESEXTRAPATHS FILE_DIRNAME HOME LOGNAME SHELL TERM USER FILESPATH USERNAME STAGING_DIR_HOST STAGING_DIR_TARGET COREBASE"
 
 MLPREFIX ??= ""
+MULTILIB_VARIANTS ??= ""