Debian uses different triples for MIPS r6 and paths.
Here we use SubArch to determine whether it is r6,
if we found `r6' in CPU section of triple.
These new triples include:
mipsisa32r6-linux-gnu
mipsisa32r6el-linux-gnu
mipsisa64r6-linux-gnuabi64
mipsisa64r6el-linux-gnuabi64
mipsisa64r6-linux-gnuabin32
mipsisa64r6el-linux-gnuabin32
This patch depends on https://reviews.llvm.org/D51408
Could you add test case for that code? To the TripleTest.cpp for example.