#2 Linux kernel compile fails with missing R_X86_64_PC64

Compiling newer Linux kernel with uClibc fail with a missing definition for R_X86_64_PC64 (not R_X86_64_64). Looks to me, the definition is missing in /usr/include/elf.h. At least inserting the definition fixed the issue for me, but I don't know if this may produce other issues. So someone familiar wit those definition shall have a look at this, before adding this to the master branch.