[oe] meson.bbclass broken on rocko

[robert_joslyn at selinc.com]

I have a build based on poky that makes use of meson.bbclass from meta-oe 
that is now broken after a recent update to OE-core. When using the latest 
rocko branches from poky and meta-oe, my meson builds end up with the 
wrong paths to ld and libc. For example, running ldd on one of my 
binaries:

linux-vdso.so.1 (0x00007fff4f9ee000)
libc.so.6 => 
/home/robert/yocto/kiosk/poky/build/tmp/sysroots-uninative/x86_64-linux/lib/libc.so.6 
(0x00007f1136f8c000)
/home/robert/yocto/kiosk/poky/build/tmp/sysroots-uninative/x86_64-linux/lib/ld-linux-x86-64.so.2 
(0x00007f1137560000)

Those paths going into my home directory are obviously not correct. I 
bisected the issue, and commit cead3c4925d39f8adc328007d8a8c1b23cc72842 in 
openembedded-core is when the problem starts: 
https://urldefense.proofpoint.com/v2/url?u=http-3A__cgit.openembedded.org_openembedded-2Dcore_commit_-3Fh-3Drocko-26id-3Dcead3c4925d39f8adc328007d8a8c1b23cc72842&d=DwIBAg&c=zVFQZQ67ypsA9mYKSCqWmQHiVkCCaN-Gb60_N6TVnLk&r=FXexzueMZc3SeYPHXBmsGdHLENOHmHsvnD0cO1_Z0j2tHI6VqrQPNkHBCZO8dAdc&m=JSVZRc5Fq4IsIwtkdFHpTXsgF8aCQ0vP6j_F7dT5tYc&s=OutJG7fOSrT6ANwnnyxx12eHu6yepO-b2NWHJeP93x0&e=

When using the tip of rocko, I can make the issue go away by removing this 
export from meson.bbclass:
 
export LDFLAGS = "${BUILD_LDFLAGS}"

I'm not really familiar with how this works, but it looks like the change 
to BUILD_LDFLAGS in uninative.bbclass is forcing the binaries to use the 
uninative ld, which isn't desired here. I assume meson.bbclass should not 
be setting LDFLAGS using ${BUILD_LDFLAGS}.

I can send a patch removing this export, but it feels like all the exports 
in meson.bbclass are incorrect. The class has been reworked and moved to 
OE-core for sumo, so I can send a patch backporting the entire class if 
that is preferred.

Thanks,
Robert