insane.bbclass and friends: Fix sanity checks and multlib headers for n32
The n32 architecture is odd, in that it's a mips64 ABI which happens
to be 32-bit. To handle this, we need something in the environment
which can be used to distinguish it. The obvious place to stash this
is the ABI suffix, so we use "n32" as an ABI suffix. This allows
a couple of improved checks:
1. In insane.bbclass, we can use "linux-gnun32" to discern that it's
okay for a mips64 binary to be a 32-bit binary in some cases.
2. In multilib_header, we can check for the n32 ABI, and use a distinct
value.
3. In siteinfo, add linux-gnun32 as a synonym for linux, similar to
what's done for linux-gnux32, and tell the mips*-linux-gnun32 variants
to pick up the corresponding mips-linux site configs.
Note that the multilib header wrapper already has n32 hooks in it, there
was just nothing creating -n32 header variants.
Signed-off-by: Peter Seebach <peter.seebach@windriver.com> Signed-off-by: Saul Wold <sgw@linux.intel.com>
