[PATCH 0/2] AIX: Do not rely on OBJECT_MODE env var being set.

Hi!

While testing --with-aix-soname=[aix|both|svr4] libtool patches within gcc,
I've discovered that gcc does not set OBJECT_MODE during multilib build.
Instead, the only settings done are: CC='xgcc -maix64' CXX='xg++ -maix64',
besides AR="$AR -X32_64" NM="$NM -X32_64" - which feels like a workaround
anyway and would be necessary for LD, STRIP and RANLIB too.

However, I've found some ABI-specific LD-flags settings in _LT_ENABLE_LOCK,
but that would be too late for checking "the name lister ($NM) interface".
Besides that, _LT_ENABLE_LOCK feels suboptimal anyway as the place to set
the ABI-specific tool flags based on created object's file type.

So I would like to introduce _LT_SET_TOOL_ABI_FLAG(TOOL, [TOOLVAR]) macro
(patch 2/2), doing something useful for power*-*-aix* for now, but designed
to adopt similar settings from _LT_ENABLE_LOCK by subsequent refactorings.

Thanks!
/haubi/