Similar to 806761a7629df268c8aed49657aeccffa6bca449
-mtriple= specifies the full target triple while -march= merely sets the
architecture part of the default target triple (e.g. Windows, macOS),
leaving a target triple which may not make sense.
Therefore, -march= is error-prone and not recommended for tests without a target
triple. The issue has been benign as we recognize xcore-apple-darwin as ELF instead
of rejecting it outrightly.
r182680 replaced CountLeadingZeros_32 with a template function
countLeadingZeros that relies on using the correct argument type to give
the right result. The type passed in the XCore backend after this
revision was incorrect in a couple of places.
Patch by Robert Lytton.
llvm-svn: 185430
