[OE-core] db failure due to libstdc++.so host contamination

[Jack Mitchell]

do_compile.log: http://ix.io/9Ki

Speaking on IRC it seems that host systems with /usr/lib/libstdc++.so
present are failing to build db.

/usr/lib/libstdc++.so is present on at least archlinux in the gcc-libs
and gcc-multilibs package which is a fairly standard package to have
installed. The problem has appeared since commit
a484b35b818768487ff27cf06b8c5d4e128126af in oe-core.

Will try and find some time to do more debugging but if anyone sees any
tell tale signs then shout up.

-- 
  Jack Mitchell (jack at embed.me.uk)
  Embedded Systems Engineer
  Cambridgeshire, UK
  http://www.embed.me.uk
--