WAF cross builds need a target specific pkg-config

[aviks]

$ TARGET=$target ./waf --prefix=${prefix} configure
....
Checking for waf version in 1.8.4-2.1.0  : ok
Checking for program 'x86_64-linux-gnu-gcc' : cc
Checking for program 'x86_64-linux-gnu-pkg-config' : not found
Could not find the program ['x86_64-linux-gnu-pkg-config']

[giordano]

Just create a symlink?

[Keno]

I think it's reasonable to put the symlink in the shard.