Fix a bug introduced during the transition to PathV2.

sys::fs::createUniqueFile returns an absolute path, so MakeSharedObject does
too and we don't need to add a './' prefix.

Patch by Jon McLachlan.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203931 91177308-0d34-0410-b5e6-96231b3b80d8
x86: getCalleeSavedRegs() would crash on 0 (so don't default to it)

The current logic assumes that MF is not 0.  Assert that it isn't, and
remove the default of 0 from the header.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203934 91177308-0d34-0410-b5e6-96231b3b80d8
[docs] Add links to XMOS XCore documentation.

Summary: Add links to XCore ISA and ABI documents.

CC: llvm-commits, rafael

Differential Revision: http://llvm-reviews.chandlerc.com/D2981

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203936 91177308-0d34-0410-b5e6-96231b3b80d8