This patch adds a test for MIPS64R6 relocations, it corrects check
expressions for R_MIPS_26 and R_MIPS_PC16 relocations in MIPS64R2 test, and
it adds run for big endian in MIPS64R2 test.
Patch by Vladimir Radosavljevic.
Differential Revision: http://reviews.llvm.org/D11217
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246311 91177308-0d34-0410-b5e6-96231b3b80d8